bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cholecystokinin causes contraction of the pupillary sphincter in monkeys but not in cats, rabbits, rats and guinea‐pigs: antagonism by lorglumide
Authors: BILL A. , ANDERSSON S. E. , ALMEGÅRD B. 
Published: December 2008

The effects of intracameral injections of cholecystokinin (CCK) on the pupil size were determined in monkeys, cats, rabbits, rats and guinea‐pigs. In animals under muscarinic cholinergic blockade, CCK caused miosis in monkeys but not in the other species investigated. In monkeys CCK‐8 was more potent than CCK‐33, which was, however, much more potent than non‐sulphated CCK‐8. These observations indicate that peripheral type A receptors mediated the miotic response. The effect of CCK‐8 was not appreciably influenced by pretreatment with indomethacin, 3 mg kg‐1 body wt, indicating that prostaglandins were not involved in the response. Nerve blockade with 0.9 μg tetrodotoxin intracamerally had no clear effect on the dose‐response relationship for CCK‐8. The effect of the peptide thus seems to be directly on receptors on the pupillary sphincter muscle. Pretreatment with lorglumide caused a dose‐dependent rightward shift of the dose–response curve, indicating competitive antagonism.The results indicate that in monkeys, but not in rabbit, cats, rats and guinea‐pigs, CCK is a potent miotic with a direct effect on the pupillary sphincter mediated by type A CCK receptors on the muscle.
Permeability of the respiratory tract to different‐sized macromolecules after intratracheal instillation in young and adult rats
Authors: FOLKESSON H. G. , WESTRÖM B. R. , KARLSSON B. W. 
Published: December 2008

The markers, bovine IgG (BIgG, mol. wt = 150000 Da) and bovine serum albumin (BSA, mol. wt = 67000 Da) together with I‐deamino‐cysteine‐8‐D‐arginine vasopressin (dDAVP, mol. wt = 1067 Da), were intratracheally instilled into young and adult rats and their passages via the respiratory tract were assessed as immunoreactive marker levels in blood serum.In the adult rats (100–120 days old) the BSA serum levels peaked 16–24 h after instillation and with a calculated transferred amount (bioavailability) of 4.3 ± 1.7 to 5.6 ± 1.4% of the dose given (five resp. 50 mg kg‐1body wt). BIgG passed via the respiratory tract with a maximum at 16 h, and with a transferred amount of 1.5 ± 0.3%, while dDAVP serum levels peaked at I h and with a transferred amount of 20 ± 4%. For the 30‐day‐old rats, similar passage time curves were obtained as for the adult, but the transferred amount was lower for BIgG (0.7 ± 0.3%), similar for BSA (4.1 ± 1.1%) and higher for dDAVP (45 ± 16%). The serum levels of BSA increased linearly with increasing dose instilled (2.5–200 mg kg‐1body wt), indicating a passive transepithelial transport route.The results show that macromolecules pass via the respiratory tract into the circulation of the rat in mainly intact forms and in high amounts, compared with passage via the GI tract. There appears to exist an inverse relationship between the molecular weights of instilled molecules and the transferred amount, a relationship affected by the development of the lung.
Plasma catecholamines, corticosterone, glucose and fatty acids concentrations and mean arterial pressure and body temperature in haemorrhagic hypovolaemia, hypothermia and a combination of these in the rabbit
Authors: HANHELA R. , HOLLMEN A. , HUTTUNEN P. , HIRVONEN J. 
Published: December 2008

Venous plasma noradrenaline, adrenaline, dopamine, corticosterone, glucose and free fatty acid concentrations were measured in anaesthetized rabbits during hypovolaemia, hypothermia and a combination of these. The anaesthetic used was Hypnorm, which contains fentanyl and fluanisone. In the hypovolaemia group blood was shed via the venous cannula until the mean arterial pressure was 50 mmHg. The rabbits in the hypothermia group were cooled in iced water to a central temperature of 32 °C, and the rabbits in the combined hypovolaemia‐hypothermia group were bled until hypovolaemic and then cooled in iced water to a central temperature of 32 °C. Rewarming was done in dry air at 43 °C.Bleeding and hypothermia activated the sympathicoadrenal system, causing a rise in the noradrenaline and adrenaline concentrations, as well as a rise in corticosterone. There were no significant differences in plasma noradrenaline and adrenaline values between the groups, whereas hypovolaemia alone also increased the dopamine concentration. In the hypothermia group the amount of corticosterone after cooling and rewarming was higher than in the combined group. Hypothermia and hypovolaemia increased the level of free fatty acids and blood glucose, which in the hypovolaemia group remained higher after volume replacement than in the other groups. Hypothermia in both groups increased the mean arterial pressure.In conclusion, the results suggest that hypothermia may prevent some harmful effects of hypovolaemia, e.g. by correcting mean arterial pressure, thus preventing the mortality seen in the hypovolaemia group.
Multiunit neural responses to strong finger pulp vibration. II. Comparison with tactile sensory thresholds
Authors: SCHMIDT R. F. , WAHREN L. K. 
Published: December 2008

In a companion microneurographic study (Schmidt et al. 1990) maximal multiunit sensory responses to finger pulp vibration were compared with maximal responses evoked by electrical stimulation of the digital nerve. It was found that the MR/ER ratio, i.e. the ratio between the magnitudes of the responses to mechanical and electrical stimulation, decreased with increasing age. The shape of this age‐related decline in the ratio corresponded well with the decrease in the number of Meissner corpuscles found in histological studies.In the present study the tactile sensory detection thresholds were measured in the same subjects that participated in the companion study and the relationship between these thresholds and the MR/ER ratios was examined. The tactile sensory detection threshold increased with age. A weak negative correlation was found between the threshold and the ratio. However, after compensation for common age‐mediated effects, this negative correlation disappeared. Thus, the results indicate that measurement of tactile sensory detection thresholds and determination of MR/ER ratios may complement each other, giving an indication of different types of derangement of the mechanoreceptive system.
Effects of electrical stimulation on eccentric and concentric torque‐velocity relationships during knee extension in man
Authors: WESTING S. H. , SEGER J. Y. , THORSTENSSON A. 
Published: December 2008

The purpose of this study was to examine the effects of electrical stimulation on torque output during knee extension. Nine well‐trained males (19–43 years) performed maximal voluntary, electrically evoked and superimposed eccentric and concentric knee extensions at velocities of 60, 180 and 360 ‘s‐’, plus an isometric test (torque was always recorded at a 60± knee angle). Fifty‐hertz stimulation was applied percutaneously at the maximum tolerated voltage (140–200 V). By superimposing electrical stimulation, eccentric torque could be increased by an average of 21–24% above the voluntary level (P < 0.05). No corresponding differences were observed between superimposed and voluntary torques under isometric or concentric conditions. Electrically evoked torque also exceeded voluntary torque under eccentric conditions (11–12%, P < 0.05), but was less under isometric and concentric conditions (‐ 10 to ‐52%, P < 0.05).Within the limitations of the study, it was concluded that eccentric knee extension torque under maximal voluntary conditions does not represent the maximal torque‐producing capacity. The action of a neural inhibitory mechanism was proposed as an explanation for this finding. If active, this mechanism may protect against the extreme muscle tension that could otherwise develop under truly maximal eccentric conditions.
Effects of eccentric and concentric muscle actions in resistance training
Authors: COLLIANDER E. B. , TESCH P. A. 
Published: December 2008

The adaptive responses to two different resistance training regimens were compared. Healthy males performed five sets of either 12 maximum bilateral concentric (Grp CON; n = 11) or six pairs of maximum bilateral eccentric and concentric (Grp ECCON; n = 11) quadriceps muscle actions three times per week for 12 weeks. Uni‐ and bilateral eccentric and concentric peak torque at various angular velocities, vertical jump height and three‐repetition maximum half‐squat were measured before and after training. Muscle biopsies were obtained from m. vastus lateralis and analysed for fibre type composition and area using histochemical techniques.In contrast to a control group (n = 7), performing no training, Grps CON and ECCON demonstrated marked increases (P < 0.05) in overall eccentric (19 and 37% respectively) and concentric (15 and 26% respectively) peak torques. Grp ECCON, however, showed greater (P < 0.05) increases in peak torque, vertical jump height and three repetition maximum than Grp CON. The 7% increases in slow‐twitch fibre area in Grps CON and ECCON and in fast‐twitch fibre area in Grp CON were nonsignificant.This study suggests that increases in peak torque and strength‐related performance parameters were greater following a programme consisting of maximum concentric and eccentric muscle actions than resistance training using concentric muscle actions only. Because increases in muscle fibre areas were small it is also suggested that the increased muscle strength shown subsequent to short‐term accommodated resistance training is mainly due to neural adaptation.
Polyamines and long‐term disuse of rat parotid glands
Authors: NILSSON B.‐O. , ROSENGREN E. , EKSTRÖM J. 
Published: December 2008

Nilsson, B.‐O., Rosengren, E. & Ekström, J. 1990. Polyamines and long‐term disuse of rat parotid glands. Acta Physiol Scand 140, 105–109. Received 1 February 1990, accepted 7 April 1990. ISSN 0001–6772. Department of Physiology and Biophysics, University of Lund and Department of Pharmacology, University of Gothenburg, Sweden.A decrease in nerve reflex activation for 7–14 days, induced by a liquid diet, caused the rat parotid gland to lose weight, involving reduction in both cell size and number. In the atrophied glands, the activity of ornithine decarboxylase, the key enzyme in polyamine formation, and the levels of the polyamines putrescine, spermidine and spermine were found to be lowered. The present results are compatible with a role for polyamines in cellular growth.
Role of opioid receptors in the long‐lasting blood pressure depression after electric muscle stimulation in the hind leg of the rat
Authors: HOFFMANN P. , DELLE M. , THORÉN P. 
Published: December 2008

In a previous study, electrically induced contractions of the gastrocnemius muscle in conscious spontaneously hypertensive rats were shown to induce a blood pressure reduction of 15–20 mmHg lasting several hours. We showed in that study that endogenous opioid systems were involved.In this study, drugs with selective affinity for different opioid receptors were used to analyse further the involvement of endogenous opioid systems in the post‐stimulatory drop in blood pressure in spontaneously hypertensive rats. Prestimulatory intra‐cerebroventricular administration of β‐FNA (a preceptor antagonist) did not significantly influence the response at all, nor did a lower intravenous dose of naloxone reverse the post‐stimulatory drop in blood pressure. High‐dose naloxone (15 mg kg‐') increased post‐stimulatory blood pressure by around 10 mmHg. About 50% of the drop thus remained after this treatment. A similar, partial reversal of the decreased blood pressure was seen after intravenous administration of a & receptor antagonist, ICI 154, 129. However, the depressor response was completely reversed by a low intravenous dose of MR 2266 BS (a K‐receptor antagonist).These results suggest that the reduction in blood pressure after muscle stimulation is mainly mediated by the opioid k‐receptor. A certain involvement of the δ‐receptor is also indicated.
Release of endothelin‐like immunoreactivity in relation to neuropeptide Y and catecholamines during endotoxin shock and asphyxia in the pig
Authors: PERNOW J. , HEMSEN A. , HALLEN A. , LUNDBERG J. M. 
Published: December 2008

The changes in endothelin‐like immunoreactivity in plasma during various provocations in the pig were investigated and related to those of neuropeptide Y, noradrenaline and adrenaline. Release as revealed by overflow was determined in the spleen, kidney and femoral vascular bed (skeletal muscle) simultaneously by collecting local venous and arterial blood samples. Under basal conditions there was no net release of endothelin‐like immunoreactivity from any region but a net removal (negative overflow) over the kidney. Endotoxin administration (20 μgkg‐1h‐1for 4 h) increased arterial endothelin‐like immunoreactivity, neuropeptide Y‐like immunoreactivity, noradrenaline and adrenaline seven‐, 27–, 100– and 166‐fold respectively, as well as splenic and renal vascular resistance. An increased overflow of endothelin‐like immunoreactivity, neuropeptide Y‐like immunoreactivity and noradrenaline, indicating local release, was observed in the spleen during endotoxin administration. The arterial plasma endothelin‐like immunoreactivity during endotoxaemia correlated significantly with the splenic and renal vasoconstriction (r =0.75 and 0.68 respectively). Chromatographic characterization revealed that the main portions of arterial plasma endothelin‐like immunoreactivity collected during endotoxaemia corresponded to synthetic endothelin‐1 and big endothelin. A similar uptake (50–90%) and plasma half‐life (1–2 min) of exogenous endothelin‐L‐like immunoreactivity was observed both under control conditions and after endotoxin, suggesting that elevated plasma endothelin‐like immunoreactivity after endotoxin was the result not of reduced clearance but rather of enhanced release. Asphyxia for 2 min did not increase arterial endothelin‐like immunoreactivity but evoked an increased overflow of endothelin‐like immunoreactivity, neuropeptide Y‐like immunoreactivity and noradrenaline as well as vasoconstriction in the spleen. Capsaicin induced a release of neuropeptide Y‐like immunoreactivity and noradrenaline from both the spleen and the kidney and of adrenaline from the adrenal, but no detectable overflow of endothelin‐like immunoreactivity from any of the vascular regions. Renal nerve stimulation, renal artery occlusion for 30 min, haemorrhagic shock, hypotension induced by nitroprusside infusion or serotonin did not cause any detectable increase in arterial plasma levels or local overflow of endothelin‐like immunoreactivity.It is concluded that plasma levels of endothelin‐like immunoreactivity are increased, suggesting release in the pig in response to endotoxin administration and asphyxia. The possible involvement of endothelin as a mediator of the peripheral vasoconstrictor responses during these situations remains to be further established.
Neurophysiological evidence for and characterization of the post‐ganglionic innervation of the adrenal gland in the rat
Authors: CARLSSON S. , SKARPHEDINSSON J. O. , JENNISCHE E. , DELLE M. , THORÉN P. 
Published: December 2008

The aim of this study was to examine and characterize the post‐ganglionic innervation of the adrenal gland, using a neurophysiological nerve recording technique.Adrenal multifibre nerve activity was recorded in chloralose‐anaesthetized Wistar rats. To test for post‐ganglionic nerve activity, trimethaphan, a ganglionic blocker, was given intravenously. About 60% of the adrenal nerve preparations tested responded with a marked decrease in nerve activity (to 52 ± 11% of pre‐trimethaphan activity, P < 0.01), while other nerves responded with an increase in activity (to 152 ± 29% of pre‐trimethaphan activity, P < 0.01). Based on these responses, the nerves were considered to contain predominantly post‐ or preganglionic fibres respectively, and the difference in response to an intravenous injection of trimethaphan between the two groups was significant (P < 0.01).It was also demonstrated that the post‐ganglionic adrenal nerve activity had a greater variability in firing pattern than preganglionic adrenal nerve activity. We also examined whether there was any cardiac rhythmicity in the investigated nerves. There was a weak cardiac rhythmicity in six out of 12 post‐ganglionic adrenal nerves, but there was no cardiac rhythmicity in the remaining six post‐ganglionic nerves, and we observed no cardiac rhythmicity in preganglionic nerves. In contrast, renal sympathetic nerves showed a profound cardiac rhythmicity.Our results might explain recent histological findings of a direct post‐ganglionic innervation of the adrenal cortex. We speculate that this nerve population is involved in steroid synthesis indirectly via regulation of the cortical blood flow or directly via a direct innervation of parenchymal cells in the adrenal cortex.
Electric muscle stimulation in the spontaneously hypertensive rat induces a post‐stimulatory reduction in activity: role of different opioid receptors
Authors: HOFFMANN P. , SKARPHEDINSSON J. O. , THORÉN P. 
Published: December 2008

We have previously shown that prolonged low‐frequency muscle stimulation, inducing contractions of the gastrocnemius muscle, in conscious spontaneously hypertensive rats leads to an opioid‐mediated post‐stimulatory reduction in blood pressure and analgesia. In the present study we investigated whether muscle stimulation would also induce a post‐stimulatory reduction in behavioural activity in the spontaneously hypertensive rats. Selective opioid receptor antagonists were used to analyse the involvement of endogenous opioids.Muscle stimulation, lasting 60 min, induced a post‐stimulatory sedation that outlasted the stimulation for hours. Sniffing, locomotor activity and total behavioural activity were significantly reduced. The post‐stimulatory reduction in activity was reversed back to control levels by a high dose of naloxone (15 mg kg‐1i.v.). The selective μreceptor antagonist, β‐funaltrexamine, given intracerebroventricularly before stimulation, did not influence the development of the post‐stimulatory drop in activity. The δ‐receptor antagonist ICI 154,129 had no effect at all on the already developed sedation, whereas MR 2266 BS, a k‐receptor antagonist (3 mg kg‐1i.v.), completely reversed the drop in activity.These results show that muscle stimulation gives rise to an opioid‐mediated post‐stimulatory reduction in activity in spontaneously hypertensive rats. The results also indicate the involvement of the opioid k‐receptor in the behavioural response.
Effects of parasympathetic decentralization on some nerve‐mediated functions in the feline urinary bladder
Authors: ANDERSSON K.‐E. , ATTA M. A. , ELBADAWI A. , LARSSON B. , MATTIASSON A. , SJÖGREN C. 
Published: December 2008

Isolated detrusor muscle from control cats and cats parasympathetically decentralized for 3 and 10 weeks responded to electrical field stimulation by tetrodotoxin‐sensitive, frequency‐dependent contractions. There were no significant differences in the frequencies producing 50% response. However, the amplitude of the scopolamine‐resistant contraction was distinctly lower in decentralized bladder preparations than in controls. Decentralized detrusor muscle (10 weeks) showed no increased response to α‐adrenoceptor stimulation (phenylephrine, clonidine, noradrenaline), but the sensitivity to carbachol (at 3 and 10 weeks) was significantly decreased compared with controls. The release of [3H]noradrenaline was decreased by carbachol 10‐7 to 10‐5 both in controls and in decentralized (10 weeks) detrusor muscle, the decrease being significantly more pronounced in the decentralized group at carbachol concentrations of 10‐7 and 10‐6. There were no differences between controls and decentralized bladders of muscarinic receptor concentration, but decentralization significantly reduced the affinity for the radioligand used to label the receptors.Thus, the main changes caused by parasympathetic decentralization of the feline bladder seem to be a reduced post‐junctional, but an increased prejunctional response to muscarinic receptor stimulation.
Calcitonin treatment of immobilization osteoporosis in rats
Authors: TUUKKANEN J. , JALOVAARA P. , VÄÄNÄNEN K. 
Published: December 2008

We studied changes in bone mass induced by immobilization and the ability of salmon calcitonin to inhibit immobilization osteoporosis in rat. The bone mass of the immobilized hind leg of rat was compared with the contralateral non‐treated leg. Neurectomy and cast immobilization reduced the bone mineral mass to an equal extent. However, the dose‐response of calcitonin was different with these immobilization techniques. Calcitonin 15 IU kg‐1 administered once daily reduced bone ash weight difference significantly after 2 weeks' neurectomy (P < 0.001). This had no significant effect on the bone loss induced by cast immobilization, but the dose had to be delivered as two injections given every 12 h. Two weeks' immobilization decreased the incorporation of 45Ca into bones. Calcitonin could not prevent this. However, calcitonin tended to inhibit the overall incorporation of 45Ca into bones in immobilized rats but yet had no effect on 45Ca incorporation in non‐immobilized rats.Immobilization decreased serum alkaline phosphatase activity in cast‐immobilized animals. Neurectomy did not change serum alkaline phosphatase activity from a sham operation level. The tartrate‐resistant acid phosphatase to total acid phosphatase ratio in the serum increased significantly in neurectomized rats and in cast‐immobilized calcitonin‐treated rats.
Responses to eccentric and concentric resistance training in females and males
Authors: COLLIANDER E. B. , TESCH P. A. 
Published: December 2008

The adaptive responses to 12 weeks of accommodated resistance training were compared in females (n= 11) and males (n= 11). They performed four to five sets of six maximum bilateral coupled concentric and eccentric quadriceps muscle actions at 1.05 rad s‐1 three times per week. Uni‐ and bilateral concentric and eccentric peak torque at different angular velocities (0.52, 1.57 and 2.62 rad s‐1), three repetition maximum half‐squat and vertical jump height were measured before and after training.Both groups displayed marked increases (P < 0.05) in concentric and eccentric peak torque at all angular velocities. The relative increases (P < 0.05) in unilateral concentric (26 vs. 26%) and eccentric (28 vs. 36%) peak torque across speeds were similar in females and males. The corresponding increases (P < 0.05) in bilateral concentric and eccentric peak torque across speeds were 20 vs. 28% and 24 vs. 39% respectively. The three repetition maximum half‐squat (20 vs. 25%) and vertical jump height (10 vs. 8%) increased (P < 0.05) equally in females and males.These results suggest that the overall increases in concentric and eccentric peak torque and functional strength, in response to short‐term accommodated resistance training, occur at a rate that is independent of sex. The torque‐velocity relationship, however, appears to change in males suggesting a relatively greater enhancement of maximum voluntary force in the slow‐speed, high‐force region.