Effect of cimetidine on weight gain in rats.

Effect on food intake and body weight was studied in rats after oral administration of cimetidine. Rats in experimental (E) group exhibited less increase in food intake (20%) compared to control (C) rats (43.8%). Mean body weight showed first reduction (-9.56%) and then very small increment in experimental animals compared to gradual gain in body weight in control animals. At the end of 6 weeks, total gain in body weight was 22.5 gm in rats of E group against 53.8 gm in rats of C group. Food efficiency ratio (FER) showed much reduction (1.13) in E group against 2.07 in C group. These results demonstrate that cimetidine (H2-receptor blocker) may have ability to reduce food intake and body weight in rats.

Autonomic functions in chronic severe anaemia.

The autonomic functions were evaluated in uncomplicated chronic severe anaemia. Elevation of heart rate and systolic blood pressure without any alteration of diastolic blood pressure were observed in anaemics as compared to control group. Expiration/inspiration ratio and BVL did not show any significant difference in two groups. The results suggest possibility of increased activity of sympathetic part out of two divisions of autonomic nervous system.

Circanual variation of sperm count and motility in men.

Seasonal variation in rhythmicity of spermatogenesis might be due to external temperature fluctuation which could partially be responsible for decreased sperm counts in summer. Other factor like exposure to light might contribute for the reduction in sperm counts. These facts should be taken into account before diagnosing male fertility.

Cardiovascular responses to cold pressor test: a test for autonomic functions.

Circulatory dynamics during the cold pressor test, done by immersing the hand in water at 5 degrees C for one minute, were studied in 30 male healthy volunteers. All the subjects responded to the test with statistically significant increase in blood pressure (22.04%, p less than 0.001), heart rate (11.21%, p less than 0.001), galvanic skin resistance (36.17%, p less than 0.001) and decrease in forearm blood flow (40.85%, P less than 0.001). The measurement of cardiovascular responses following cold pressor test constitutes another test which can be used to test the efficiency of the autonomic nervous system in various autonomic neuropathies.

Role of vagal and sinoaortic baroreflexes in restoration of arterial pressure after acute mild haemorrhage in rabbits.

To evaluate the contribution of vagal and sinoaortic baroreflexes (SBR) in circulatory adjustments, anaesthetized rabbits were subjected to acute mild haemorrhage and the extent of recovery produced after haemorrhage was estimated. The recovery of arterial pressure after acute mild haemorrhage with reflexes intact was 96.19%, after elimination of SBR it was 79.20%, after bilateral vagotomy 87.38%, and after eliminating both reflex systems it was 75.66%. The results suggest that vagally mediated baroreflexes from cardiopulmonary baroreceptors contribute significantly in restoring the arterial pressure in response to haemorrhage while the sinoaortic baroreflexes play the major role.

Baroreceptor reflexes in postural control of circulation in rabbits.

The present study was undertaken to evaluate reflex cardiovascular responses to postural stress in rabbits. The changes in mean arterial pressure (MAP) and heart rate (HR) were monitored in the supine position and following sudden passive head up tilt (HUT), and head down tilt (HDT) to 70 degrees. The results show a significant increase in MAP (18.57%, P less than 0.001) and HR (2.92%, P less than 0.02) with HUT; and a marked decrease in MAP (43.48%, P less than 0.001) and HR (8.21%, P less than 0.001) with HDT (as compared to the values in supine position). The changes in MAP were found to be more marked than those in HR. The depressor responses to HDT were more marked than the pressor responses to HUT.

Decreased tolerance to orthostatic stress in diabetics.

Cardiovascular responses to head up tilt (HUT) were investigated in chronic diabetics (having disease of 8 to 10 years duration) and in control subjects. The parameters recorded were heart rate (HR), blood pressure (BP), forearm blood flow (FABF) and forearm vascular resistance (FAVR). Recordings were made first in the supine position, next after HUT, and thirdly in the recovery period after return to the supine position. Normal subjects responded to HUT by a marked increase in HR (P less than 0.001), decrease in FABP (P less than 0.001) and increase in FAVR (P less than 0.001). The diastolic blood pressure (DBP) and mean blood pressure (MBP) showed appreciable increase (P less than 0.001, P less than 0.01 respectively) without significant fall in systolic blood pressure (SBP). The maximum alteration in cardiovascular responses was observed immediately after HUT (within 15 sec). The cardiovascular responses to HUT in diabetics were found to be significantly impaired compared to control subjects. The impairment of cardiovascular responses in diabetics in indicative of autonomic neuropathy which can be detected by these tests before the development of clinical signs of the neuropathy.

The influence of muscle use on conduction velocity of motor nerve fibres.

The conduction velocity of the motor nerve fibres of the peroneal and posterior tibial nerves was estimated in 38 rickshaw pullers and 25 human volunteers serving as controls. The mean values for motor conduction velocity were greater in the case of rickshaw pullers as compared to control subjects. However, the difference was statistically significant (P smaller than 0.05) for the peroneal nerve only. It is concluded that muscle hypertrophy produced by hyperactivity has an influence on nerves supplying the muscles.

Bilateral asymmetry in conduction velocity in the efferent fibres of the median nerve andits relationship to handedness.

The conduction velocity in the efferent fibres of the median nerve has been compared in the right and left forelimbs of 38 human subjects. Six independent estimates were made for each limb. Estimates on the right and left limb of a subject were made at the same sitting. Conduction velocity was faster on the right side in the majority of right handed subjects; and on the left side in the majority of left handed subjects. The mean conduction velocity was greater on the right side in right handed subjects (P less than 0.02).