bluuebunny/crossref_metadata_2025_split huggingface dataset:
The relationship between corpuscles of Stannius and serum electrolyte regulation in killifish, Fundulus heteroclitus
Authors: Pang Peter K. T. 
Published: June 2005

AbstractCorpuscles of Stannius were surgically removed from male killifish, Fundulus heteroclitus, acclimated to one third Long Island Sound sea water. Asthenia and kidney stone formation were observed. An increase in serum total and dialytic calcium, chloride and potassium and a decrease in serum sodium and inorganic phosphate were evident. No change in serum magnesium was observed. Injections of homogenates of codfish corpuscles of Stannius into intact male killifish adapted to fresh or sea water produced a significant decrease in serum total calcium in sea water fish only.
Function of the parathyroid gland of the snake, Thamnophis sirtalis
Authors: Clark Nancy B. 
Published: June 2005

AbstractGarter snakes, Thamnophis sirtalis, have four parathyroid glands that are similar histologically to those of other reptiles. A high percentage of the animals also possess accessory parathyroid tissue. Complete parathyroidectomy of the snakes produced severe depression of serum calcium values, tetanic convulsions, and significant elevation of serum phosphate within several weeks of the operation. Administration of mammalian parathyroid extract to normal snakes had the opposite effects, elevating serum calcium and depressing serum phosphate concentrations. In contrast, mammalian calcitonin preparations did not significantly affect serum calcium or phosphate values.The parathyroid glands of snakes thus function to maintain normal neuromuscular coordination by regulating blood calcium and phosphate concentrations.
Growth and metabolic effects of prolactin and growth hormone in the red‐spotted newt, Notophthalmus viridescens
Authors: Brown Patricia S. , Brown Stephen C. 
Published: June 2005

AbstractGrowth hormone, administered in doses of 4 and 20 μg every other day for five weeks, caused a significant increase in length and weight in the newt Notophthalmus (Triturus) viridescens. Prolactin, similarly administered in the same amounts, likewise increased body length, but failed to elicit a significant body weight increase. Prolactin also caused increased liver weight and liver carbohydrate while growth hormone was without significant effect on the liver. Four weeks of treatment with 4 μg GH/day or 4 μg prolactin/day was without effect on gonad size.
Effect of mammalian insulin on plasma glucose in the mud puppy (Necturus maculosus)
Authors: Copeland Danny L. , DeRoos Roger 
Published: June 2005

AbstractThe effect of mammalian insulin on plasma glucose levels was studied in the paedogenic urodele amphibian, Necturus maculosus. Blood was collected from a cannula implanted in the dorsal aorta via the gastric artery and plasma glucose was estimated by the glucose oxidase method. Plasma glucose levels of untreated animals were 31.6 ± 1.6 mg% at the completion of the operation and then declined to 14.1 ± 2.5 mg% on the third post‐operative day; the levels remained relatively stable from the third through the fifth day when sampling was terminated. Subsequent experiments began on the third post‐operative day. “Normal” plasma glucose levels were judged to be too low to demonstrate a statistically significant insulin effect and a glucose tolerance study was performed to elevate plasma glucose. Plasma glucose levels were 9.3 ± 1.6 mg% before glucose administration and were 68.8 ± 4.2 mg% at 30 minutes after the infusion via the cannula of 25 mg glucose per 100 gm body weight. Plasma glucose levels declined 52% at 3 hours, 75% at 6 hours, and to approximately the pre‐treatment levels at 24 hours after the infusion. The effect of insulin on the decay curve of infused glucose was determined. Control animals received glucose and the hormone‐free carrier; experimental animals received glucose and 10 IU insulin per 100 gm body weight. Plasma glucose levels were not significantly lower than those of the controls at 30 minutes after the infusion, but were significantly lower at all subsequent sampling times (3, 6, 9, 12, 24, 48 hours) and were less than 3 mg% from 12 through 48 hours; no hypoglycemic symptoms were noted even in animals without detectable plasma glucose. The data indicate that plasma glucose is not a required source of energy in the mud puppy.
The role of the lizard thyroid gland in tail regeneration
Authors: Turner James E. , Tipton Samuel R. 
Published: June 2005

AbstractHypothyroidism in Anolis carolinensis caused almost a two week delay in blastema formation and tail elongation was completely inhibited. Hormonal replacement therapy (L‐thyroxine) in hypothyroid lizards allowed for normal blastema formation as well as subsequent tail elongation.Hyperthyroidism in Anolis initiated the early development and subsequently the early completion of blastema formation but had no significant effect on tail elongation.Histological observations in the hypothyroid regenerates when compared with those receiving thyroxine replacement revealed that: (a) the inhibition of tail elongation was due to an inhibition of the outgrowth of the ependyma into the developing blastema; (b) although tail elongation was inhibited in hypothyroid lizards, many tissues within the blastema did differentiate along the same time course as those found in hormonal replacement regenerates and controls; thus, thyroxine apparently had little to do with tissue differentiation in these animals.Hypophysectomy was found to delay blastema formation by one and one‐half weeks and to inhibit tail elongation in the same manner as was found in hypothyroid lizards. A dose response relationship was found to exist between certain levels of thyroxine (0.04 to 0.2 μg) and tail regeneration in hypophysectomized lizards. The intermediate dose of thyroxine (0.2 μg) produced a maximum response with respect to lizard tail elongation. A greater dose of thyroxine (1.0 μg) did not further augment the regeneration process and any greater dose would likely produce an inhibitory effect.
Cytochrome oxidase activity during amphibian development
Authors: Boell Edgar J. , D'Anna Tommaso , Greenfield Phyllis , Petrucci Delio 
Published: June 2005

AbstractChanges in cytochrome oxidase (COX) activity during development have been determined in homogenates of embryos of five species of amphibia: Rana esculenta, Rana pipiens, Amblystoma punctatum, Bufo americanus, and Xenopus laevis. When inhibitory substances produced by skin are removed or compensated for by bovine serum albumin, COX increases several fold throughout the period of prefeeding development in all species studied. The increase is interpreted as synthesis of COX accompanying production of new mitochondria. The rate of increase is considerably greater after the tail bud stage has been reached and appears to be associated with a period of general protein synthesis reported by others. DPNH‐cytochrome‐c reductase activity and respiration of intact embryos have been determined in Rana pipiens for comparison with COX. The developmental changes in general parallel those of COX but at quantitatively different levels.
Relationship of genotype and degree of chimerism in coat color to sex ratios and gametogenesis in chimeric mice
Authors: Mullen R. J. , Whitten W. K. 
Published: June 2005

AbstractGenotype and the degree of chimerism expressed in the coat color of chimeric (allophenic) mice were found to be related to the frequency of multicolored chimeras, the sex ratio, and the production of gametes. The sex ratios of 310 chimeric mice of various combinations of genotypes were studied. The male: female ratios varied from 1:1 to ratios approaching 3:1. Multicolored chimeras in which one genotype predominated (“unbalanced” genotypes) had normal sex ratios of 1:1 (19 ♂ ♂, 21 ♀ ♀ ) suggesting that sex was determined by the predominating component. Multicolored chimeras in which neither component predominated (“balanced” genotypes) had sex ratios approaching 3:1 (70 ♂ ♂, 31 ♀ ♀ ) suggesting that most sex chimeras (XX ⟷ XY) develop as phenotypic males. Regardless of genotype, solid colored chimeras had normal sex ratios. Only two hermaphrodites (0.65%) were observed.A high incidence of gonadal mosaics which produced progeny with both parental genotypes and a relatively low incidence of possible sex chimeras which produced progeny with only one genotype occurred among multicolored females. A very low incidence of gonadal mosaics and a very high incidence of possible sex chimeras was found among males. These observations would be expected if most sex chimeras developed as phenotypic males.
Instability of the epithelial‐mesenchymal interaction in the eight‐day embryonic chick thyroid
Authors: Hilfer S. Robert , Stern Mark 
Published: June 2005

AbstractBy using cells from the eight‐day chick embryo to study epithelial‐mesodermal interaction in the thyroid we have confirmed the results previously reported for the mature cells of the 16‐day gland. The cells, which do not yet possess a canaliculate endoplasmic reticulum, fail to develop these channels in monolayer culture. After seven days of spreading, the membranes are as sparse as they were in the eight‐day embryo and closely resemble those in cells of the 16‐day gland after a week of spreading. This lack of organization is in sharp contrast to the elaborate system of interconnecting channels of the 16‐day gland or the eight‐day gland which has been in organ culture for seven to eight days.Reaggregation of the eight‐day monolayers has revealed the necessity of cells from the thyroid capsule for normal differentiation. Young and mature epithelial cells give basically the same responses to fibroblasts from heterologous organs. In both cases, histogenesis is abnormal. Aggregates prepared with capsule of the young gland result in necrosis of spread eight‐day epithelial cells and cord formation by spread 16‐day epithelial cells. Cells from the capsule of the 16‐day thyroid, on the other hand, produce normal thyroid when combined with either the 8‐ or 16‐day epithelium.The results are compared with those from investigations of the epithelial‐mesenchymal interaction in other organs.
Expression of paternal genes during embryogenesis in the viable interspecific hybrid amphibian embryo Rana pipiens ♀ × Rana palustris ♂. Electrophoretic analysis of five enzyme systems
Authors: Johnson Kurt E. , Chapman Verne M. 
Published: June 2005

AbstractGenetic differences in enzyme electrophoretic mobility have been used to determine the time of expression of paternal genes during embryogenesis in the viable interspecific hybrid amphibian embryo Rana pipiens ♀ × R. palustris ♂. Maternal isozymes for lactate dehydrogenase (LDH), 6‐phosphogluconate dehydrogenase (6‐PGD), glutamate‐oxaloacetate transaminase (GOT), glucose phosphate isomerase (GPI), and malate dehydrogenase (MDH) persist in unfertilized eggs and one, two, and three day embryos. Paternal type bands for 6‐PGD, GOT, and GPI appear at four days of development, when embryos are late Stage 19 and early Stage 20. Paternal bands for LDH and MDH appear at five days of development, when embryos are late Stage 20. These results are discussed in terms of paternal gene expression and the genomic control of early amphibian development.
Development of the rat salivary glands. I. Accumulation of parotid gland DNase activity
Authors: Ball William D. 
Published: June 2005

AbstractThe parotid gland of the rat contains high levels of a secretory DNase with a substrate preference for native DNA, requirement for divalent cations (Mg+ +) and pH optimum at 7. 5. This enzyme appears not to be found in the submaxillary‐sublingual gland complex, which has only a low level of DNase activity with a contrasting substrate preference for denatured DNA. Neonatal submaxillary and parotid glands both contain a constant, low level of activity which is similar in magnitude to that of the adult submaxillary gland. DNase activity in the neonatal parotid begins to increase between 10‐ and 15‐days post‐partum and rises 10,000‐fold by 30‐days. The substrate preference of the low DNase activity present in the parotid gland prior to ten days was determined for newborn rats, and was found similar to the adult submaxillary rather than to the adult parotid enzyme, since the newborn extract preferentially hydrolyzed denatured DNA. These results support the working hypotheses; that the parotid gland DNase is not found in the other salivary glands and is thus a specific marker of parotid differentiation, and that the synthesis of this enzyme in the parotid gland does not begin until after ten days post‐partum.The results obtained here are discussed in terms of the possible relationships between early tissue interactions in the embryonic gland rudiments and their later assumption of a cell‐specific pattern of protein synthesis, and these relationships are compared to those found in previous analyses of the embryonic pancreas (Rutter et al., '67a). It is suggested that the regulation of specific cytodifferentiation in the salivary glands may be basically different in mechanism than that of the pancreas.
In vitro induction of ovulation and oocyte maturation in Rana pipiens ovarian follicles: Effects of steroidal and nonsteroidal hormones
Authors: Schuetz Allen W. 
Published: June 2005

AbstractIndividual ovarian follicles of Rana pipiens respond to hormonal stimuli in vitro. The relative effectiveness of progesterone and gonadotrophic hormones in initiating ovulation and oocyte maturation were compared. Maturation of oocytes (>99%) with limited concomitant ovulation resulted following treatment of follicles with progesterone. Frog pituitary tissue was less effective than progesterone in stimulating maturation, but was more effective in producing ovulation. Neither ovulation nor maturation was stimulated in response to the mammalian gonadotrophic hormones (FSH, LTH, PMS, HCG) or mammalian growth hormone. Mammalian LH produced both ovulation and maturation; furthermore, no synergistic interaction with FSH was observed. Maturation did not occur in response to the gonadotrophic hormones without a concomitant, but not necessarily equivalent, induction of ovulation. Follicular responsiveness, particularly to gonadotrophic hormones, was affected by animal and seasonal variations. Structural changes (follicular membrane detachment from the oocyte) were observed in unovulated follicles treated with hormones. The structural alterations were closely correlated with the induction of oocyte maturation. These observations suggest that (1) the intrafollicular events leading to ovulation and maturation are not equally sensitive to pituitary and progesterone stimulation, (2) maturation and ovulation activities of gonadotrophins are probably inseparable, (3) responsiveness of follicles to specific gonadotrophins is not related to only their FSH or LH activity. These data are consistent with the hypothesis that gonadotrophins act indirectly via the follicular tissues to initiate the processes of ovulation and maturation.
Temporal effects of ovine luteinizing hormone and desoxycorticosterone acetate on maturation and ovulation of oocytes of the catfish, Heteropneustes fossils (Bloch): An In vivo and In vitro study
Authors: Goswami Shashi V. , Sundararaj Bangalore I. 
Published: June 2005

AbstractIntramuscular administration of ovine luteinizing hormone (LH) or desoxycorticosterone acetate (DOCA) into gravid catfish, Heteropneustes fossilis, shows that LH is a much less efficient maturation‐inducing agent than DOCA. Maturational changes occur two hours earlier following DOCA injection than with LH. In the second experiment, ovarian pieces obtained from catfish one to eight hours following LH or DOCA injection were cultured in Wolf and Quimby medium without hormones for 11 to 4 hours respectively; the total duration between hormone injection and termination of culture was 12 hours in every case. Oocytes sampled from catfish two hours after DOCA injection or four hours after LH injection completed the process of maturation in vitro in the absence of hormones. Further, oocytes obtained from DOCA‐injected catfish three, four and five hours after treatment and cultured for nine, eight and seven hours respectively, exhibited maturational changes far more advanced than in the oocytes of the corresponding LH‐injected groups. In LH‐injected catfish maturational changes were observed two hours later than those in DOCA‐injected group. It is suggested that this two‐hour time lag, noticed in both the experiments, represents the duration necessary for LH to act on the catfish interrenal to build up the circulating titers of corticosteroids required for maturation and ovulation of oocytes. It is tentatively concluded that the terminal hormones which act on the catfish oocytes to induce maturation and ovulation are the corticosteroids.
Factors directing the expression of sympathetic nerve traits in cells of neural crest origin
Authors: Cohen Alan M. 
Published: June 2005

AbstractIt has been assumed that the phenotype expressed by a particular cell of neural crest origin is determined by the tissues comprising the final site of that crest cell. To test this premise as it applies to differentiation of sympathetic ganglioblasts, the future site of the primary sympathetic ganglia was ablated from embryonic axial trunks and the remaining tissues including the migrating crest cells were grown on chorioallantoic membranes of host chicks. Despite removal of the ultimate site of the primary sympathetic chains, catecholamine‐containing cells, identified by a fluorescent test, differentiated ectopically.These results suggest that tissues along the migratory route rather than the tissues comprising the definitive site direct catecholamine synthesis in crest cells. To test this possibility, segments of neural tubes containing neural crest were grown alone or combined with somites on the chorioallantoic membrane. It was found that sympathoblast differentiation requires the presence of somitic mesoderm. In addition, ablation of the ventral neural tube drastically reduces the quantity of sympathetic nervous tissue formed in the presence of somites. Whether the ventral neural tube affects the crest cells directly or affects the capacity of the somites to influence crest cell differentiation is as yet undetermined. Control experiments indicate that mesoderm from other sources will not substitute for the somites in eliciting differentiation of sympathoblasts. These experiments support the hypothesis that neural crest cells give rise to sympathetic neurons in response to conditions imposed while the cells migrate ventrally.
Physiological responses of larval and postmetamorphic Rana pipiens to growth hormone and prolactin
Authors: Snyder Benjamin W. , Frye B. E. 
Published: June 2005

AbstractBovine prolactin stimulates growth of tadpoles, whereas bovine growth hormone stimulates growth of postmetamorphic frogs. The biochemical composition of liver, muscle, and fat body were examined to determine whether there were any changes in carbohydrate, protein, fat, or nucleic acids which might correlate significantly with the growth effects of the hormones in the two stages of development. In the frog, the major effect of growth hormone was to depress carbohydrate and lipid stores, with little or no effect on protein and nucleic acids in most experiments. Prolactin had similar but smaller effects on carbohydrate, and no effect on fat body lipid in the frog. In tadpoles prolactin suppressed muscle glycogen, but otherwise did not affect tissue composition. Growth hormone had no effects in the tadpole. Ways in which the interrelated developmental and metabolic effects of growth hormone and prolactin could increase the adaptive significance of distinct larval and postmetamorphic growth‐regulating hormones in the amphibians are discussed.
Histological observations on allografts and reciprocal xenografts in newts (Notophthalmus viridescens) and axolotls (Ambystoma mexicanum)
Authors: Taban Charles H. , Connelly Thomas G. 
Published: June 2005

AbstractA histological study, involving autoradiography of tritiated thymidine labelled host: and graft, was performed in reciprocal skin grafts between Notophthalmus viridescens and Ambystoma mexicanum. The histoanatomical differences in the two types of skin appear to interfere in the rejection processes. The adepidermal membrane and dermal collagen, as well as the activity of the host epithelial cells, are stressed as factors playing a role in the rejection rate of the graft.
The effect of prolactin on the seasonal cyclicity of newt forelimb regeneration
Authors: Schauble Muriel K. , Tyler David B. 
Published: June 2005

AbstractA cyclic seasonal variation in forelimb regeneration in the newt, Notophthalmus viridescens, was noted under controlled environmental conditions at 20°C in previous experiments. Regeneration was enhanced in the summer months and reached its maximum linear growth rate in late spring‐early summer. It was suggested that this variation might be due to hormonal influences.The pituitary hormone prolactin was selected for study because it has been shown to support regeneration in hypophysectomized newts and to enhance regeneration in the intact newt, in the intact newt more effectively than growth hormone. Experiments in winter and summeri were performed to determine whether prolactin alone enhanced regeneration and what effect it might have on the seasonal variation in regeneration.The results clearly show enhancement of regeneration by intraperitoneal injections of prolactin in both summer and winter. The hormone increases the rate of linear growth and initiates early finger differentiation. The increase in linear growth rate persists throughout the 90‐day observation period. Prolactin does not enhance regeneration beyond the spontaneous optimum regenerative period in late spring‐early summer noted in previous experiments. Prolactin eliminates the seasonal variation in regeneration, and it is possible that the seasonal cycles are due to changes in output of this hormone.
Trout intestinal alkaline phosphatases I. Some physical‐chemical characteristics
Authors: Whitmore Donald H. , Goldberg Erwin 
Published: June 2005

AbstractFour electrophoretic zones of trout intestinal alkaline phosphatase are described on the basis of charge and molecular weight heterogeneity. Qualitative and quantitative differences in the intestinal phosphatase complement suggest three basic phenotypes, which are exemplified by the isozyme patterns of wild brook trout, hatchery brook trout, and lake trout.The partially purified and separated trout phosphatase zones have been characterized physically and chemically. The data presented clearly place these enzymes in the category of the non‐specific alkaline phosphomonoesterases. In common with this group of enzymes, trout phosphatases catalyze the hydrolysis of a wide variety of phosphomonoesters and pyrophosphates, as well as transphosphorylation reactions.