bluuebunny/crossref_metadata_2025 huggingface dataset:
PREIMPLANTATION CHANGES AFTER LITTER REMOVAL FROM SUCKLING MICE
Authors: BINDON B. M.
Published: December 2008

Delayed implantation in suckling mice was interrupted by litter removal at 08.00 hr. on day 5 of lactation pregnancy. A number of preimplantation changes were examined at intervals of 2, 8 and 32 hr. after litter removal. Control groups which retained their litters were examined at similar times. Litter removal was followed by significant reduction in pituitary folliclestimulating hormone (FSH) in the 2 and 8 hr. groups. The earliest uterine response to litter removal was the incorporation of [3H]uridine. This was significantly increased by 8 hr. and was about four times the control values by 32 hr. after litter removal. Increased uterine capillary permeability and the development of dye sites were not observed until 32 hr. after litter removal. At this time the number of zygotes flushed from the uterus was significantly lower than in controls, indicating that attachment of the blastocyst to the uterus had commenced. These results indicate that delay of implantation induced by suckling is associated with increased pituitary FSH. Litter removal causes prompt release of FSH and increased oestrogenic activity in the uterus (i.e. uridine incorporation) as early as 8 hr. later.
THE LYSINE-VASOPRESSIN TEST: AN EVALUATION OF TWO METHODS OF ADMINISTRATION IN NON-CORTICOSTEROID-TREATED AND CORTICOSTEROID-TREATED PATIENTS WITH RHEUMATOID ARTHRITIS
Authors: SHENKIN A. , NUKI G. , LINDSAY R. M. , WHALEY K. , DOWNIE W. W. , DICK W. C.
Published: December 2008

The response of plasma 11-hydroxycorticosteroids (11-OHCS) to parenteral lysine-vasopressin (LVP) was studied in 47 patients with rheumatoid arthritis, 25 of whom had received long-term oral corticosteroid therapy; the remaining 22 had received no oral corticosteroids at any time, and served as controls. Both groups of patients showed excellent reproducibility of the plasma 11-OHCS response to LVP, when administered intravenously or intramuscularly. Comparable plasma 11-OHCS levels were reached in control patients when the intravenous LVP test was carried out in the morning and in the evening. Criteria of a normal response to both intramuscular and intravenous LVP were defined. In the control group, intravenous infusion of LVP led to a more sustained plasma 11-OHCS response than did intramuscular injection of the same dose. No such differences were observed in the corticosteroid-treated group, but the intramuscular test was subnormal more frequently than the intravenous test.

In the control patients, insulin-induced hypoglycaemia and intravenous LVP led to comparable plasma 11-OHCS response, although a higher mean level at 60 min. was observed in the former. This difference was not observed in the corticosteroid-treated patients.

Direct comparison of these three tests lead to the conclusion that the intramuscular LVP test is more sensitive than the intravenous LVP test, but less sensitive than the insulin hypoglycaemia test, in detecting corticosteroid-induced suppression of hypothalamo-pituitary-adrenal function. The intramuscular LVP test is therefore to be preferred to the intravenous test because of its greater sensitivity, its relative lack of side-effects, and its ease of performance.
CLINICAL AND BIOCHEMICAL STUDIES OF A PATIENT WITH A HILUS CELL TUMOUR
Authors: MORI T. , YOSHIDA Y. , NISHIMURA T. , KONO T. , YAMADA S. , TATSUMI S.
Published: December 2008

A 27-year-old patient with a hilus cell tumour of the ovary giving rise to secondary amenorrhea and marked virilization was studied clinically and endocrinologically, and the tumour was examined by light and electron microscopy. Clinical, roentogenological and endocrinological studies showed that the ovarian tumour was the source of excessive androgen production. Urinary 17-oxosteroid excretion was always higher than 65 mg./day. The urinary production rates of testosterone, dehydroepiandrosterone and dehydroepiandrosterone sulphate were 1970 mg./day, 98·5 mg./day and 31·9 mg./day, respectively. Postoperatively, the androgenic manifestations gradually subsided, and the menstrual cycle returned to normal.
CHANGES IN THE PERMEABILITY OF THE TESTICULAR CAPILLARIES AND OF THE 'BLOOD-TESTIS BARRIER' AFTER INJECTION OF CADMIUM CHLORIDE IN THE RAT
Authors: SETCHELL B. P. , WAITES G. M. H.
Published: December 2008

Blood flow, capillary permeability and the entry of rubidium into the testis, epididymis, skeletal muscle and brain of male rats were examined within 6 hr. of giving an s.c. injection of cadmium chloride (3 μmole/100g. body wt). Sapirstein's (1958) indicator fractionation technique was used to measure blood flow with [125I]iodoantipyrine and simultaneously capillary permeability and rubidium uptake were assessed using 131I-labelled human serum albumin and [86Rb]rubidium chloride respectively.

Blood flow in the testis and the initial segment of the caput of the epididymis increased in the first 2 hr. after cadmium administration, returned to control levels at 3 hr., and thereafter sharply decreased. Labelled albumin began to accumulate in extravascular compartments 3–4 hr. after cadmium; in the head of the epididymis this increase in capillary permeability appeared earlier than in the testis and preceded the fall of blood flow.

The limited transport of rubidium into the seminiferous tubules was again observed and used as a criterion of tubular integrity. The uptake of 86Rb by the testis increased within 2 hr. of giving cadmium and thus preceded the extravascular transport of albumin from the capillaries. This is the earliest indication of cadmium damage to the tubules so far reported. There were no systematic changes in these parameters in the rest of the epididymis, skeletal muscle or brain.
THE FATE OF VERY SMALL LITTERS PRODUCED BY EGG TRANSFER IN MICE
Authors: McLAREN ANNE
Published: December 2008

Varying numbers (2–12) of fertilized eggs from donor mice 3½ days post coitum were transferred to the uteri of pseudopregnant recipients 2½ days post coitum. A higher proportion of blastocysts than of morulae implanted and developed into live foetuses. The number of eggs transferred did not affect the proportion which implanted. Litters of one or two young, resulting from the transfer of two eggs to one horn only, were successfully carried to late pregnancy and suffered less post-implantational mortality than did larger litters resulting from the transfer of larger numbers of eggs.

An empty uterine horn did not exert either a systemic or a local luteolytic effect. Eggs were transferred to one horn of a pseudopregnant female, and at the same time the ovary on that side was removed. Implantation occurred normally, pregnancies were maintained, and the corpora lutea in the remaining ovary did not appear to be affected by the adjacent unoccupied horn.

When litters of one or two young were allowed to go to term, the young suffered very heavy perinatal mortality. This was not a direct effect of the small number of young, but was entirely due to the significant prolongation of the gestation period with small litters, combined with the significant decrease in perinatal survival when parturition was delayed.
ULTRASTRUCTURAL EVIDENCE FOR THE STIMULATION OF NUCLEAR RIBONUCLEIC ACID SYNTHESIS BY OESTRADIOL-17β IN THE VAGINAL EPITHELIUM OF THE OVARIECTOMIZED MOUSE
Authors: POLLARD IRINA
Published: December 2008

The cytochemical nature of the ultrastructural nucleolar transformation previously observed in the vaginal epithelium of the ovariectomized mouse after local application of oestradiol-17β was investigated using a recently developed ultrastructural staining technique. Oestradiol treatment induced ribonucleic acid (RNA) synthesis, especially in the nucleolus but also in the nuclear chromatic region and ribosomes. Actinomycin D administered simultaneously with oestradiol reduced the oestrogen-induced nucleolar response to the control level. These findings are discussed with special reference to the mode of action of oestrogens.
KINETIC STUDIES ON THE BIOSYNTHESIS OF CORTICOSTEROIDS IN VITRO FROM EXOGENOUS PRECURSORS BY THE INTERRENAL GLANDS OF THE NORMAL, CORTICOTROPHIN-TREATED AND ADENOHYPOPHYSECTOMIZED XENOPUS LAEVIS DAUDIN
Authors: CHAN S. T. H. , EDWARDS B. R.
Published: December 2008

Incubation of the adrenocortical tissue of Xenopus with labelled steroidal precursors gave aldosterone, corticosterone, 11-deoxycorticosterone and 18-hydroxycorticosterone as the major products. Kinetic studies indicated that the major biosynthetic pathway in Xenopus is the same as that in the duck, cobra and frog, and follows the sequence: pregnenolone → progesterone → 11-deoxycorticosterone → corticosterone → aldosterone + 18-hydroxycorticosterone.

The effects of adenohypophysectomy and of injection of mammalian corticotrophin (ACTH) on the corticosteroidogenetic capacity of Xenopus were also studied. The production of both aldosterone and corticosterone increased after ACTH administration and decreased markedly after adenohypophysectomy. Some of the evidence suggests that ACTH was effective at biosynthetic stages following the formation of pregnenolone. The present studies on corticosteroid production were done in conjunction with parallel investigations on osmoregulation and electrolyte and water changes in Xenopus (Edwards, 1969).
KINETICS OF DISTRIBUTION OF RADIOACTIVE PERCHLORATE IN RAT AND GUINEA-PIG THYROID GLANDS
Authors: CHOW SIEN YAO , WOODBURY D. M.
Published: December 2008

The thyroidal uptake of 36ClO4− and the effect of stable perchlorate ion and functional state of the thyroid, such as after long-term administration of propylthiouracil (PTU) or after hypophysectomy, on the uptake of 36ClO4− were studied in rats and guinea-pigs. Based on the analysis of uptake curves, radioactive inulin and sulphate spaces, and histological measurements of compartmental sizes of the thyroid, the relative concentrations of 36ClO4− in the various compartments were calculated and compared with those of 36Cl-. The passage of 36ClO4− and 36Cl− across both the basal and the apical membranes of the follicular cells in the different conditions were analysed. The results suggest that 36ClO4− is concentrated in the lumen of the thyroid by a two-step process. It is actively transported across the basal cell membrane from the interstitial fluid into follicular cells, and is further concentrated in passage across the apical membrane into the lumen. The evidence suggests that the latter process is also an active one.
ADRENAL FUNCTION IN BREAST CANCER: BIOGENESIS OF ANDROGENS AND CORTISOL BY THE HUMAN ADRENAL GLAND IN VIVO
Authors: DESHPANDE N. , JENSEN VIBEKE , CARSON PAMELA , BULBROOK R. D. , DOOUSS T. W.
Published: December 2008

A variety of 14C and 3H-labelled steroids have been perfused through the human adrenal gland in situ and their metabolic products isolated from adrenal venous blood.

Progesterone, dehydroepiandrosterone and cortisol were isolated after infusion of [3H]pregnenolone; 17α-hydroxyprogesterone, dehydroepiandrosterone and cortisol after infusion of [3H]17α-hydroxypregnenolone and [14C]progesterone; androstenedione and cortisol after infusion of [3H]17α-hydroxyprogesterone and [14C]dehydroepiandrosterone; and 11β-hydroxyandrostenedione after infusion of [3H]androstenedione and [14C]cortisol.

From a consideration of the incorporation of radioactivity into the metabolic products, the3H: 14C ratios and the tissue pool sizes it was concluded that the major biosynthetic pathway to cortisol in the human adrenal glands was: pregnenolone→ 17α-hydroxypregnenolone → cortisol. Progesterone was not an important intermediary.

Androstenedione was mainly formed by way of 17α-hydroxypregnenolone → 17α-hydroxyprogesterone → androstenedione. 11β-Hydroxyandrostenedione was formed mainly from cortisol and only a minor amount came from the hydroxylation of androstenedione.
PATHWAYS OF STEROID BIOSYNTHESIS IN THE INTACT GRAAFIAN FOLLICLE OF MARES IN OESTRUS
Authors: YOUNGLAI E. V. , SHORT R. V.
Published: December 2008

Two mares were operated on during oestrus; in the first animal a mixture of [16-3H]pregnenolone and [4-14C]androstenedione was injected into the largest Graafian follicle; in the second animal, [4-14C]pregnenolone and [7-3H]androstenedione were injected into the follicle. By cannulating the ovarian veins it was possible to measure the rate of transfer of radioactivity from the follicular fluid into the ovarian vein. This ranged from 3 to 9% of the injected dose per hour. At the end of each experiment, 45–52 min. after the injection of the labelled precursors, the follicular fluid was aspirated. Negligible amounts of radioactivity were recovered from the rest of the ovary and from the 'conjugated' fraction of the ovarian vein plasma and follicular fluid. Within the follicle 6·2 and 12·2% of the injected pregnenolone were converted to progesterone. Further metabolism to 17 α-hydroxyprogesterone, androstenedione and oestradiol-17β was very limited. Oestradiol-17β isolated from the ovarian vein had a higher specific activity than that from the follicular fluid while the 3H: 14C ratios were similar in both compartments. In addition, the 3H:14C ratios of androstenedione and oestradiol-17β in the ovarian vein were similar. Therefore it seems likely that oestradiol-17β in the follicular fluid is derived mainly from an extra-follicular source, probably the theca interna cells.
THE ACTION OF DIBUTYRYL CYCLIC 3′,5′-ADENOSINE MONOPHOSPHATE ON THE MOUSE THYROID GLAND IN VITRO
Authors: KENDALL-TAYLOR PAT , MUNRO D. S.
Published: December 2008

The effects of dibutyryl cyclic 3′,5′-adenosine monophosphate (DBc-AMP) on the mouse thyroid gland have been investigated in the in-vitro assay of Brown & Munro (1967). The distribution of 131I-labelled compounds in the glands and the supporting medium have been analysed by thin-layer chromatography and the changes induced by cyclic 3′,5′-adenosine monophosphate (c-AMP), DBc-AMP or thyroid-stimulating hormone (TSH) compared.

The release of 131I was increased when the glands were incubated with DBc-AMP, c-AMP or TSH. The potency of DBc-AMP was approximately 50 times that of c-AMP on a basis of molarity. Like TSH, DBc-AMP increased the proportion of iodothyronines in the system as a whole, whereas c-AMP had little effect. The possible explanations for this are discussed.
EFFECT OF GONADOTROPHINS ON THE OESTROUS CYCLE IN THE GUINEA-PIG
Authors: DAS R. M. , BENSON G. K.
Published: December 2008

Adult virgin, regularly cyclic female guinea-pigs were treated with different doses of luteinizing hormone (LH) and follicle-stimulating hormone during the late luteal phase of the oestrous cycle. The onset of the next oestrus was delayed and the length of the dioestrous stage was prolonged beyond the normal range in all the treated groups, but for a maximum period in the animals receiving LH alone.

The results indicate a dual role of LH on the normal cycle of the guineapig. It has been suggested that either luteotrophin release from the pituitary or an intrinsic luteotrophic action is probably a part of the function of LH in addition to its ovulation-inducing function in the guinea-pig.
A POSSIBLE ROLE FOR THE ADENYL CYCLASE SYSTEM IN CALCITONIN RELEASE
Authors: CARE A. D. , BATES R. F. L. , GITELMAN H. J.
Published: December 2008

A possible role of the adenyl cyclase system in calcitonin (CT) release has been investigated by measurement of the rate of CT secretion in isolated porcine thyroid glands perfused in situ. Dibutyryl cyclic AMP increased the rate of secretion of CT and this effect was enhanced by theophylline. Concentrations of glucagon as low as 1·4 nm (5 ng/ml) induced a significant increase in the rate of CT secretion when precautions were taken to prevent enzymic degradation of glucagon. This stimulatory effect of glucagon on CT secretion was also increased by theophylline. Significant stimulation of CT release was demonstrated with adrenaline in the presence of α-adrenergic blockade with phentolamine and could be inhibited by β-adrenergic blockade with propranolol. In contrast, thyrotrophin, tri-iodothyronine, serotonin, parathyroid hormone and cyclic guanosine monophosphate had no significant acute effects on CT secretion. It is suggested that the C-cells of the thyroid gland contain an adenyl cyclase system similar to that described in other tissues and that physiological concentrations of glucagon and catecholamines may influence the response of the C-cell to plasma calcium concentration.
URINARY AND BILIARY EXCRETION OF [4-14C]PROGESTERONE, [4-14C]20α- AND [4-14C]20β-HYDROXYPREGN-4-EN-3-ONE METABOLITES IN THE RABBIT
Authors: SENCIALL I. R. , THOMAS G. H.
Published: December 2008

[4-14C]Progesterone, [4-14C]20α- and 20β-hydroxypregn-4-en-3-one were injected intravenously into deeply anaesthetized rabbits and the bile and urine collected for 6 h. Neutral metabolites recovered after Ketodase hydrolysis of bile accounted for a mean of 82·8% (range 68·0–98·8%), 68·4% (61·0–80·0%) and 59·0% (57·0–61·0%) of the metabolites of progesterone, 20α-and20β-hydroxypregn-4-en-3-one, respectively. Acidic metabolites accounted for no more than 14·7% of the biliary radioactivity. Similar recoveries of neutral metabolites were obtained after hydrolysis of bile with 15% HCl, but only 41·0% (22·2–62·0%), 45·3% (36·4–55·4%) and 13·7% (10·6–16·9%) of the urinary metabolites were extractable as neutral metabolites. Acidic metabolites represented a further 33·9% (28·9–49·5%), 34·9% (27·5–40·4%) and 38·6% (29·4–47·8%) of the urinary radioactivity, respectively.

Neutral ether soluble metabolites more polar than 5β-pregnane-3α,20α-diol were the most abundant metabolites. 3α-Hydroxy-5β-pregnan-20-one was identified in the bile as a metabolite of [4-14C]progesterone whereas 20α-hydroxypregn-4-en-3-one was present in the urine. 5β-Pregnane-3α, 20α-diol was identified as a biliary metabolite of [4-14C]20β-hydroxypregn-4-en-3-one.
THE EFFECTS OF THYROTROPHIC HORMONE AND OF THYROXINE ON THE RESPONSE OF THE SEBACEOUS GLANDS OF THE RAT TO TESTOSTERONE
Authors: EBLING F. J. , EBLING ERIKA , SKINNER J.
Published: December 2008

Treatment with thyrotrophic hormone (TSH) significantly enhanced the action of testosterone in increasing sebum secretion in both castrated and hypophysectomized—castrated male rats. The dose of TSH, equivalent to about 0·1 i.u./24 h for 24 days, was insufficient to increase thyroid weight, even though this was only half of normal in the hypophysectomized—castrated rats.

Treatment with thyroxine (T4) significantly added to the action of testosterone in increasing sebum production in castrated rats, but the effect was accompanied by a decreased incidence of mitoses in the sebaceous glands.

Treatment with propylthiouracil did not by itself affect sebaceous activity in castrated rats, nor did it inhibit the action of testosterone. Sebum secretion in castrated animals treated with propylthiouracil and testosterone was significantly higher than in those treated with testosterone alone.

In view of the evidence that TSH and T4, although similar in their effects on sebum secretion, appeared to act in opposite ways on the incidence of sebaceous mitoses, and that the response of the sebaceous glands to testosterone was increased rather than inhibited by treatment of the rats with propylthiouracil, it is concluded that the action of TSH in enhancing the sebaceous response is more likely to be direct than indirect by stimulation of the thyroid gland.
INTERRELATIONSHIP OF THE EFFECTS OF ALDOSTERONE AND THYROID HORMONES ON SODIUM TRANSPORT AND ELECTRICAL PROPERTIES OF RAT COLON
Authors: EDMONDS C. J. , THOMPSON B. D. , MARRIOTT JANE
Published: December 2008

Transmucosal electrical potential difference (p.d.), short-circuit current, electrical resistance and Na+ influx rate of the descending colon were similar in euthyroid and hypothyroid rats, the latter having been treated earlier with an ablation dose of 131I. However, in contrast to the considerable p.d. increase found in normal rats, little change of p.d. was found in hypothyroid rats when they were Na+ depleted or given an intravenous aldosterone infusion. A single small dose of tri-iodothyronine (T3) (1 μg/100g body weight) or a larger dose of thyroxine given to hypothyroid rats 10–16 h before aldosterone, restored the p.d. response to normal, although these doses did not influence the animal's oxygen consumption. Fasting for 3 days or giving actinomycin D (8 μg/100 g body weight) abolished the effect of T3 but this did not influence the action of aldosterone in euthyroid animals.
SUBCELLULAR LOCALIZATION OF NEUROTRANSMITTERS AND RELEASING FACTORS IN THE RAT MEDIAN EMINENCE
Authors: CLEMENTI F. , CECCARELLI B. , CERATI E. , DEMONTE M. L. , FELICI M. , MOTTA M. , PECILE A.
Published: December 2008

The neurohaemal part of the median eminence of the rat hypothalamus is characterized by numerous nerve terminals which end near a rich network of fenestrated capillaries. An attempt was made to isolate different types of nerve terminals by means of sucrose density-gradient centrifugation. The subcellular fractions obtained were assayed for dopamine, noradrenaline and 5-hydroxytryptamine. In addition FSH- and GH-releasing activities were determined. A sample of each fraction obtained was taken for electron microscopical observations.

Dopamine, noradrenaline, 5-hydroxytryptamine, GH- and FSH-releasing factors were present in higher concentration in the nerve endings. A further fractionation showed that noradrenaline was present in the lightest synaptosomal band, dopamine in the middle one, and 5-hydroxytryptamine in the heaviest. GH-RF and FSH-RF were recovered mainly from the band containing dopamine. The relevance of this localization to the physiological role of the median eminence is discussed.
THE PLASMA GROWTH HORMONE CONCENTRATION OF THE FOETAL LAMB
Authors: BASSETT J. M. , THORBURN G. D. , WALLACE A. L. C.
Published: December 2008

Growth hormone (GH) concentrations in the plasma of foetal lambs (range 20–150 ng/ml) were ten or more times those in the plasma of ewes during the last third of pregnancy. Blood samples obtained from foetuses with indwelling vascular catheters indicated that there was a steady rise in foetal plasma GH concentrations from 40–50 ng/ml at 100–110 days gestation to maximum values of 110–120 ng/ml between 130 and 140 days gestation and then a rapid decrease around the time of birth.

Growth hormone disappeared from the foetal plasma after hypophysectomy of the foetus and there was no evidence for a placental source of the hormone. Ovine pituitary growth hormone given by intravenous injection disappeared from the foetal plasma at a similar rate to the endogenous hormone following hypophysectomy. The rate of GH removal from foetal plasma was slower than that in lambs 4–12 days after birth.

Glucose infusion into foetal lambs did not alter their plasma GH concentration significantly, but infusion of the catecholamine, isoprenaline, decreased the foetal plasma GH concentration rapidly. Cessation of infusion was followed by very rapid restoration of the former high plasma GH concentration. The results indicate that the high foetal plasma GH concentration is maintained by active secretion of the hormone, but its function in the foetal lamb remains obscure.
ALTERATION IN THE OESTROUS CYCLE LENGTH AFTER PITUITARY HOMOTRANSPLANTATION IN THE GUINEA-PIG
Authors: DAS R. M. , BENSON G. K.
Published: December 2008

Pituitaries from adult or young guinea-pigs were implanted under the kidney capsule of intact adult female guinea-pigs between the 3rd and 5th days of the oestrous cycle.

The oestrous cycles in the recipients of adult pituitaries were mostly normal in length. Seven out of nine animals engrafted with pituitaries from their own litters had a prolonged dioestrus, ranging from 8 to 16 days longer than normal, at the end of which oestrus and ovulation occurred. When the grafts contained pituitaries from one male and one female pup the cycle extension was more pronounced than when they were composed of pituitaries from two or three female pups.

The occurrence of prolonged dioestrus accompanied by a delayed ovulation in the graft-bearing animals is suggested to be associated with the production of luteotrophic hormone by the graft tissue, possibly deriving from basophil cells.
HUMAN PITUITARY FOLLICLE-STIMULATING HORMONE: DISTRIBUTION, PLASMA CLEARANCE AND URINARY EXCRETION AS DETERMINED BY RADIOIMMUNOASSAY
Authors: AMIN H. K. , HUNTER W. M.
Published: December 2008

The volume of distribution, plasma clearance and urinary recovery of human follicle-stimulating hormone (FSH) after intravenous injection has been estimated in healthy men. A human FSH-anti FSH radioimmunoassay was used which, though not completely specific, discriminates against luteinizing hormone (LH) by at least 10:1 in terms of i.u.

The half-life in the circulation was 24–38 min in three subjects who received the same dose. Urinary recovery, when expressed as a percentage of the injected dose, was 36·8 ± 7·7 (s.d.)% in nine experiments with three different doses in six subjects. The time-course and percentage recovery were similar for all doses used.
EFFECTS OF HUMAN PITUITARY EXTRACTS ON ANDROGEN BIOSYNTHESIS BY HUMAN ADRENALS IN VITRO
Authors: MILNER A. JOSEPHINE , MILLS I. H.
Published: December 2008

The effects of human pituitary extracts upon steroid biosynthesis by pieces of human adrenal tissue incubated in Krebs—Ringer bicarbonate buffer have been studied. Experiments with both adult and foetal adrenal tissue have been carried out. Radioactive precursor (either [7-3H]pregnenolone or [4-14C] progesterone) was added to each incubation vessel and the synthesis of radioactively labelled products was estimated by reverse isotope dilution. Individual steroids were characterized by paper and thin-layer chromatography; the radiochemical purity of cortisol, androstenedione, dehydroepiandrostenedione (DHA) and DHA sulphate was established following derivative formation. There was no consistent effect of the pituitary preparations upon the biosynthesis of cortisol, DHA or DHA sulphate, nor upon the ratio of cortisol to the combined production of DHA and DHA sulphate. However, the production of androstenedione from both [7-3H]pregnenolone and [4-14C]progesterone was significantly increased in the presence of pituitary and gonadotrophic preparations.
EFFECT OF HYPOPHYSECTOMY OF FEMALE RATS ON THE ACTIVITY OF PANCREATIC ELASTOLYTIC ENZYMES AND THE ELASTIN CONTENT OF HEART, LUNG AND AORTA
Authors: LOEVEN W. A.
Published: December 2008

Since previous findings suggest that the production and secretion of elastolytic enzymes by the pancreas are under endocrine control, the activity of elastoproteinase and the elastomucases Em-I and Em-S in the pancreas was determined in two groups of 19-month-old female rats. The first group of 12 animals was hypophysectomized at the age of 9 months, the second group of nine rats served as controls. The enzyme activities were measured using as substrates: unstained alkali-treated elastin and unstained and orcein-stained acid-treated elastin. Thus, data could be obtained for both the Em-I and Em-S activities. Hypophysectomy decreased the level of pancreatic elastoproteinase and increased the total activity of both elastomucases. Further, it was found that the elastin content in heart, lung and aorta of the hypophysectomized rats was increased as compared with that in the controls.
CHANGES IN THE METABOLIC CLEARANCE RATE OF PROGESTERONE IN THE GUINEA-PIG
Authors: ILLINGWORTH DOREEN V. , HEAP R. B. , PERRY J. S.
Published: December 2008

The metabolic clearance rate (MCR) of progesterone was measured by continuous infusion of the tritium-labelled steroid in guinea-pigs under light sodium pentobarbitone anaesthesia. In normal animals during the oestrous cycle, the MCR was 112·8 ± 7·0 (s.e.) 1 plasma/day/kg. In pregnant animals there was a sharp decrease in MCR between days 15 and 20, to 8·3 ± 0·8 1/day/kg. This low clearance rate was observed throughout the remainder of gestation. After parturition MCR returned slowly to non-pregnant levels, reaching 85 1/day/kg by day 12 post partum.

The decrease in metabolic clearance rate occurred at the same time as the increase in plasma concentration of progesterone. This may be related to an increase in binding proteins with a high affinity for progesterone. The stimulus for the decrease in MCR in pregnancy is obscure but appears to depend on the presence of a viable conceptus. In the non-pregnant guinea-pig the MCR is not reduced by exogenous oestrogen, hysterectomy or hypophysectomy.
FOLLICLE-STIMULATING HORMONE CONTENT OF THE PITUITARY GLANDS OF INTACT AND OVARIECTOMIZED MICE OF DIFFERENT STRAINS
Authors: KARANDE K. A. , SHETH N. A. , RANADIVE K. J.
Published: December 2008

The follicle-stimulating hormone (FSH) content of the pituitaries of intact and ovariectomized mice of the strains C3H/Jax and ICRC, which differ in their adrenocortical responses to ovariectomy was measured at different ages. It was always higher in intact ICRC than that in intact C3H mice, particularly in younger age groups. Ovariectomy caused a fivefold increase in the FSH content in C3H mice after 1 month which was maintained up to 6 months. Thereafter there was a gradual decrease up to 12 months. The increase in pituitary FSH content in ICRC mice after ovariectomy was much less and occurred at a later age. These results agree with cytological observations on the pituitaries of these two strains.
SERUM RENIN ACTIVITY DURING EXPOSURE TO HYPOXIA
Authors: TUFFLEY R. E. , RUBENSTEIN D. , SLATER J. D. H. , WILLIAMS E. S.
Published: December 2008

Changes of serum renin activity, heart rate, blood pressure, renal sodium, potassium and metadrenaline excretion and alveolar gas tensions were recorded during two 2–3 h exposures to 446 mmHg barometric pressure (simulated altitude of 4279 m or 14000 ft). Serum renin activity rose considerably during the first exposure and only slightly during the second. This effect was positively correlated with the changes of heart rate. There was little change in blood pressure or in the rate of renal excretion of sodium, potassium or the metadrenalines.

It is suggested that the change of serum renin activity cannot be explained by a direct effect of hypoxaemia, emotion, posture or the diurnal rhythm of renin secretion but that it may be correlated with changes of cardiovascular function.
EFFECT OF MESENCEPHALIC STIMULATION ON THE RELEASE OF GONADOTROPHINS
Authors: CARRER H. F. , TALEISNIK S.
Published: December 2008

Different regions of the midbrain were stimulated by electrolytic deposition of iron from stainless steel unipolar electrodes. Electrochemical stimulation of the ventral tegmental area (VTA), the raphe nuclei or the peri-aqueductal grey in rats in pro-oestrus was effective in preventing spontaneous ovulation. No blockade of ovulation was observed by stimulating other mesencephalic structures. After stimulation in the VTA there was a significant decrease of the elevated serum levels of luteinizing hormone (LH) found after an injection of progesterone into pro-oestrous rats or into ovariectomized—oestrogen-primed animals. In contrast, electrochemical stimulation of the dorsal mesencephalic tegmentum, lateral and inferior to the peri-aqueductal grey, in rats in which spontaneous ovulation had been blocked by continuous illumination, resulted in an ovulatory response. Serum LH was found to increase in gonadectomized—oestrogen-treated male and female rats after stimulating this area. No significant changes in serum follicle-stimulating hormone were found after stimulation in the ventral or dorsal tegmentum. It is concluded that both stimulatory and inhibitory influences on the release of gonadotrophin can be evoked by stimulating mesencephalic structures. The stimulatory and inhibitory effects could depend on the activation of noradrenergic and serotoninergic systems, respectively.
THE ROLE OF THE THYROID IN THE INTESTINAL EFFECT OF VITAMIN D ON RACHITIC RATS
Authors: WINTER M. , MORAVA E. , SIMON G.
Published: December 2008

The effect of 20 i.u. vitamin D3 on the intestinal absorption of calcium was investigated in thyroidectomized and control rachitic rats. Vitamin D3 increased both duodenal and jejunal calcium absorption in the absence of the thyroid glands. These results suggest that neither thyroxine nor calcitonin are necessary for the effect of vitamin D3 on intestinal calcium absorption.
PERIPHERAL PLASMA PROGESTERONE CONCENTRATION OF COWS DURING PUBERTY, OESTROUS CYCLES, PREGNANCY AND LACTATION, AND THE EFFECTS OF UNDER-NUTRITION OR EXOGENOUS OXYTOCIN ON PROGESTERONE CONCENTRATION
Authors: DONALDSON L. E. , BASSETT J. M. , THORBURN G. D.
Published: December 2008

Progesterone concentrations in the peripheral plasma of cows were measured by a protein-binding radioassay method. The mean concentration was lowest at oestrus (0·44 ng/ml) and then increased to a maximum of 6·8 ng/ml about day 14 of the 21-day cycle. The concentration decreased rapidly during the last 4 days of the cycle, reaching low levels on the day before oestrus. There were no significant changes in progesterone concentration during oestrus. After ovariectomy the plasma progesterone concentration decreased to a very low level (< 0·4 ng/ml). After hysterectomy, progesterone concentrations remained high for longer than in a normal cycle. At puberty, plasma progesterone concentrations indicated cyclic ovarian activity before the first observed oestrus.

Daily treatment of cows with oxytocin (0·4 u./kg body weight) from day 2 reduced the oestrous cycle length to 9 days, but did not significantly alter the slow increase in plasma progesterone concentration during the first 5 days of the cycle. Plasma progesterone concentrations decreased again after day 5 to low values. Plasma progesterone concentration during early pregnancy was similar to the luteal phase value (4–6 ng/ml), declined during mid-pregnancy and then increased to a maximum (7–8 ng/ml) at about 240 days gestation. The concentration declined 2–3 weeks before calving. During lactation progesterone concentrations were very low until the resumption of cyclic ovarian activity. The first post-partum cycle, whether accompanied by observed oestrus or not, was usually preceded by a small increase in plasma progesterone concentration 3–5 days before the start of the cycle.

Undernutrition significantly increased plasma progesterone concentrations in mid- and late pregnancy. Undernutrition of non-pregnant cows increased progesterone concentrations during the luteal phase of the first cycle, but reduced it in later cycles.
LACTOGENESIS IN PSEUDOPREGNANT RABBITS TREATED WITH ADRENOCORTICOTROPHIN AND ADRENAL CORTICOSTEROIDS
Authors: CHADWICK A.
Published: December 2008

The lactogenic effect of adrenocorticotrophin (ACTH) injected into pseudopregnant rabbits has been confirmed. A synthetic partial ACTH peptide (Synacthen) was also lactogenic. The sensitivity to local lactogenic stimuli of the mammary glands of ACTH-treated rabbits and rabbits treated with corticosteroids was greater than that in untreated rabbits. The findings are discussed in relation to the factors controlling lactogenesis.
STIMULATION OF THE SYNTHESIS OF MACROMOLECULES BY OVARIAN HORMONES DURING EARLY DEVELOPMENT OF THE MOUSE MAMMARY GLAND
Authors: BANERJEE M. R. , ROGERS FERNE M.
Published: December 2008

The influence of oestradiol and progesterone on nucleic acids and protein synthesis during early development of 3- to 4-week-old C3H mouse mammary gland in vivo was studied. The hormones were administered daily by subcutaneous injections for 6–9 days. Uptake of tritium-labelled appropriate nucleoside and amino acid precursors, as determined by radio-chemical and autoradiographic methods, was used as a measure of cellular biosynthesis. Administration of the steroid hormones induces a pronounced increase of RNA, protein, and DNA synthesis in the mammary parenchyma of both intact and ovariectomized mice. Increased RNA and protein synthesis were detectable after two injections of the hormones, the maximal level was reached after the 6th injection. Hormone-induced DNA synthesis rose sharply reaching a peak after four treatments. The stimulatory effect of the steroids on DNA synthesis was more pronounced on the end-bud cells up to the 4th injection but in the duct cells [3H]thymidine uptake continued to rise progressively even after the 6th injection. Autoradiographs showed that the hormones also cause a twofold increase in the silver grain count per nucleus indicating an accelerated uptake rate of the DNA precursor. In end-bud cells mitotic activity, used as a measure of cellular proliferative activity, rose to a sharp peak after four injections of the hormones but in duct cells it continued to rise even after the 6th injection. The significance of these results with respect to further lobulo-alveolar development of the mammary parenchyma is discussed.
THE LIPIDS OF THE CROP EPITHELIUM OF PIGEONS AFTER INJECTION WITH PROLACTIN FROM THE PITUITARIES OF DIFFERENT VERTEBRATE CLASSES
Authors: CHADWICK A. , JORDAN B. J.
Published: December 2008

The histological appearance, the lipid content and composition of the epithelium of the pigeon crop were investigated after intradermal injection of extracts containing prolactin from representatives of several vertebrate classes. Lipids from crop 'milk' and body depot fat were also studied. There was significantly more lipid in stimulated crop tissue than in the unstimulated crop but significantly less than in crop 'milk', which had approximately half the concentration present in depot fat. Although the lipid staining of histological sections of crops of pigeons injected with prolactin from different vertebrate classes differed strikingly, no difference in lipid concentration in the crop tissue was detected. Equally there were no striking differences between the fatty acid compositions of the triglycerides extracted from the different crops or between these and the triglycerides of crop 'milk' or depot fat. The implications of these findings regarding the effects of prolactin in the pigeon and possible attributes of prolactin from different vertebrate classes are discussed.
ENDOCRINE CONTROL OVER PRODUCTION AND ACTIVITY OF THE ANTI-AGGRESSION PHEROMONE FROM FEMALE MICE
Authors: MUGFORD R. A. , NOWELL N. W.
Published: December 2008

In an attempt to clarify the role of gonadal function in the release of anti-aggression pheromone into the urine of female mice, two experiments were carried out. Each involved recording the aggressiveness of 'fighter' male mice when presented with castrated male 'opponents' which had been treated either with urine from one of four categories of female donor mice, or with water.

In the first series of experiments it was shown that the urine from oestrous and dioestrous mice contained similar amounts of anti-aggression activity. Both spaying and testosterone propionate (TP) injection of the female urine-donors abolished this activity.

In a second series of experiments urine from spayed donors injected with TP greatly increased the aggression response to a level which exceeded that obtained with the urine of TP-treated intact mice. High doses of oestrogen resulted, in the spayed urine-donors, in an actual increase in aggression response. Both treatments increased clitoral gland weight, and it is concluded that androgen or high levels of oestrogen can stimulate the clitoral gland of the female, a possible consequence being a release of aggression-promoting pheromone.

The aggression-inhibiting pheromone, which depends on the ovary for its release, is probably the product of some other tissue, as yet unidentified.
ADRENAL STEROID SECRETION IN THE TASMANIAN DEVIL (SARCOPHILUS HARISII) AND THE EASTERN NATIVE CAT (DASYURUS VIVERRINUS). A COMPARISON OF ADRENOCORTICAL ACTIVITY OF DIFFERENT AUSTRALIAN MARSUPIALS
Authors: WEISS MAGDA , RICHARDS P. G.
Published: December 2008

Adrenal venous and peripheral blood was collected from three Tasmanian devils and three Eastern native cats.

Ten Δ4-3-oxosteroids were identified in the adrenal venous blood of the devils and nine from the native cats. Cortisol was the major steroid and its maximum corticotrophin (ACTH) stimulated secretion rate averaged 61 μg/h/100 mg adrenal in devils and 36 μg in cats. The cortisol: corticosterone ratio in two devils and two cats was approx. 2·5 and 5, respectively. Aldosterone secretion rates in devils ranged from 0·06 to 0·12 μg/h/100 mg adrenal and in cats from 0·12 to 0·93, the response to ACTH varied in different animals. 21-Deoxycortisol was found in all animals, it increased during ACTH stimulation (maximum range in devils: 8·5–19·5 μg/h/100 mg adrenal, and 0·6–5·4 in cats). Another unusual steroid isolated from adrenal venous blood was identified as 17α-hydroxy-20β-dihydroprogesterone. Its rate of secretion was higher in devils (range approx. 2–6 μg/h/100 mg adrenal). No relationship was found between adrenal blood flow and corticosteroid secretion. In the peripheral blood plasma only cortisol and corticosterone were identified. The female of both species had a significantly higher concentration of cortisol of the order of 7 μg/100 ml plasma. The combined adrenal weights/kg body weight averaged 168 mg/kg in the devils and 132 mg in the cats.

Since all three Superfamilies of Australian marsupials have now been investigated a comparison of the results obtained from seven representative species is made and they are also considered in relation to eutherian mammals.
EFFECT OF ADRENALECTOMY AND ADRENOCORTICOTROPHIC HORMONE ON SEBUM SECRETION IN THE RAT
Authors: THODY A. J. , SHUSTER S.
Published: December 2008

Adrenalectomy caused a decrease in the rate of sebum secretion of male rats.

On the other hand treatment with adrenocorticotrophic hormone (ACTH) produced a large increase in the rate of sebum secretion in hypophysectomized—castrated rats and restored it to the level in castrated rats. ACTH also stimulated sebum secretion in castrated rats after removal of the adrenals, although this increase was not significant.

These findings suggest that a pituitary—adrenal—sebaceous gland system may exist. Adrenal androgens may play a significant part in this relationship.

Although ACTH probably stimulates sebum secretion through its action on the adrenals it is possible that this pituitary hormone may have some direct effect on sebaceous gland activity.
A VERY EARLY PREGNANCY TEST FOR MAMMALS: ITS APPLICATION TO THE COW, EWE AND SOW
Authors: ROBERTSON H. A. , SARDA I. R.
Published: December 2008

A method is described for diagnosing the presence or absence of a conceptus soon after mating or insemination. It is applicable to a wide range of mammals and tests in the cow, sheep and pig have given an accuracy of approximately 90%. The method is based on the detection of a functional or regressed corpus luteum at a fixed time after mating by measuring the concentration of progesterone in peripheral blood. It is relatively simple to carry out.
THE EFFECTS OF HYPOPHYSECTOMY ON ADRENOCORTICAL FUNCTION IN THE DUCK (ANAS PLATYRHYNCHOS)
Authors: BRADLEY E. L. , HOLMES W. N.
Published: December 2008

The general effect of chronic hypophysectomy on organ and body weights, liver glycogen, blood glucose, peripheral plasma corticosterone concentrations, and blood pressure in the duck were similar to those described for several mammalian species.

The disappearance and distribution of radioactivity after the administration of [1,2-3H]corticosterone and [1,2-3H]aldosterone was studied according to a single compartment model system. When compared with sham-operated ducks, the apparent volumes of distribution and the biological half-lives of radioactivity in hypophysectomized ducks were significantly increased, and the estimated metabolic clearance rates of [1,2-3H] corticosterone and [1,2-3H]aldosterone were significantly decreased. The patterns of distribution of radioactivity and the rate of metabolism of both hormones returned towards normal when the chronically hypophysectomized ducks were treated with corticotrophin (ACTH).

Fourteen days after hypophysectomy the peripheral plasma concentration of corticosterone and the estimated rate of corticosterone secretion by the adrenal fell to 10 and 4%, respectively, of the values observed in sham-operated birds. Examinations of the peripheral plasma corticosterone concentration during the first 30 min after the removal of the adenohypophysis indicated a mean biological half-life for endogenous corticosterone of 13·7 min.

The rates of appearance of radioactivity in the bile, intestine and cloaca of the hypophysectomized birds suggested substantial declines in the rates of aldosterone and corticosterone metabolism. These declines could not be accounted for by the reduced rate of glomerular filtration in the hypophysectomized bird. Replacement therapy with ACTH restored the excretory patterns of both steroids towards normal. The quantitative similarities between the effects of hypophysectomy in the duck and several mammalian species make it unnecessary to postulate either a high degree of adrenal autonomy or an extrahypophysial source of ACTH in the control of adrenocortical function in the duck.
SOME LIGHT- AND ELECTRON-MICROSCOPICAL OBSERVATIONS ON THE PARS INTERMEDIA OF THE PITUITARY GLAND OF THE RABBIT
Authors: CAMERON E. , FOSTER C. L.
Published: December 2008

The cytological appearance of the pars intermedia of the rabbit both at the light and the electron microscopical (E.M.) levels, is described. Two types of cell,one stainable byperiodic acid—Schiff's reagent and aldehyde—fuchsin and the other chromophilic, non-granular and intercalated between the former, were observed. In E.M. sections the first type had two kinds of granule in its cytoplasm, a few electron-dense about 250 nm in diameter, mostly confined to the Golgi area, and numerous large 'vesicles' or granules of varying density about 500–600 nm in diameter generally distributed throughout the cytoplasm. The second type of cell when viewed in the electron microscope is characterized by microvilli projecting into intercellular spaces, and long, linked processes ramifying in between the principal cells. Varicose nerve fibres and abundant neurosecretory material were demonstrated in the pars intermedia with chrome alum—haematoxylin and Alcian blue. In E.M. sections these neurosecretory granules were similar to those in the infundibular process. At the point where nerve fibres appeared to be making contact with glandular cells, synaptic vesicles of about 50 nm in diameter were also observed.
THE EFFECT OF HYPOPHYSECTOMY, AND OF INJECTIONS OF THYROTROPHIN AND CORTICOTROPHIN INTO HYPOPHYSECTOMIZED ANIMALS, ON THE SLOUGHING CYCLE OF THE LIZARD, GEKKO GECKO L.
Authors: CHIU K. W. , PHILLIPS J. G.
Published: December 2008

Hypophysectomy resulted in a lengthening of the sloughing cycle for about 25 days as compared with the normal cycle. The increase is only in the resting phase, the renewal phase remains unaffected. Thyroid-stimulating hormone did not affect the epidermis directly but increased the activity of the thyroid gland in the hypophysectomized geckos as judged by the uptake of 131I and follicular cell height, and reduced the resting phase by about 7 days. Corticotrophin inhibited sloughing for at least 65 days, and possibly entirely, with the epidermis remaining in the resting condition.