Effect of cigarette smoking and 3.2% ethanol alone or together on RBC and platelet counts in rats.

The present study was conducted on 32 rats divided into four groups. Group C served as control, Group S rats were exposed to cigarette smoke alone, Group SE to cigarette smoke and ethanol (3.2%) and Group E to ethanol alone for twelve weeks. The basal RBC and platelet count were determined and compared with the values obtained at the end of 12 weeks. A significant increase in RBC and platelet counts was seen in Groups S (P < 0.001 and P < 0.01 respectively) and SE (P < 0.01 for both counts). The increase in group SE is less than that seen in Group S. Ethanol consumption alone has shown a significant decrease (P < 0.01) in RBC count and apparent decrease in platelet count as compared to control. This study indicates that cigarette smoke is damaging to health alone or when combined with ethanol.

Effect of stress on organ weight in rats.

The effect of 90 minute supine restraint or forced swim stress, on weights of various organs in sixty adult male albino rats was studied. One group of twenty rats served as control; second group of twenty was immobilized and third group of twenty was forced to swim in water at room temperature. The animals were studied for a period of 15 days. During this period, they were subjected to 90 minutes of stress everyday at the same time. Both the groups of stressed animals showed a statistically significant increase in weight of cerebrum, cerebellum, pituitary, thyroid, and adrenals. Testes and seminal vesicles showed no significant change in weight. There was an apparent increase in weight of liver after immobilization stress, and a statistically significant increase in its weight in forced swim group. Therefore, immobilization and forced swim stresses produce an increase in the weight of brain cerebrum and cerebellum, endocrine organs and liver.

Effects of adrenalectomy on brain weight, body weight and weight of certain endocrine organs in rats.

Albino rats, both males and females were adrenalectomized (Adx.), either on the eleventh or the twenty fifth day after birth and the body weights recorded daily until the sixtieth day when all the animals were sacrificed. Brain (cerebrum and cerebellum), pituitary, thyroid and gonads were weighed post mortem. Body weights decreased in all the Adx. animals, the decrease being statistically significant in the male rats Adx. on day 11 (p less than 0.05). Both cerebrum and cerebellum recorded a significant increase in weight in both the male Adx. groups, whereas pituitary, thyroid and gonads showed a significant decrease. Changes observed in 25 day Adx. female rats were not statistically significant. Thus, adrenalectomy in the young rats appears to have differential effects on the somatic, neural and endocrine growth.

Ingestive behaviour of starved rats after single intraperitoneal injection of fresh plasma from well-fed rats.

Ingestive behaviour of control and experimental rats following 96 hours of starvation was studied. The control animals were injected normal saline intraperitoneally (I.P.) whereas the experimental animals were injected I.P. with fresh plasma obtained from well fed rats. Having been presented with food 15 minutes after the injections, the food intake (Gms +/- SEM) of control animals for the first five hours after injection was 6.00 +/- 0.44, whereas, the intake in experimental animals for the same period was 0.55 +/- 0.05. The food intake was significantly suppressed for the next three days, attaining the normal values by the 4th day. Since all the rats were starved prior to injection, all of them increased in weight during the four days of study, but the increase seen in the experimental group was much subdued. Therefore the plasma factor, suppresses not only the food intake but also the gain in body weight.

Effect of immobilization stress on food intake, body weight and weights of various organs in rat.

Effect of immobilization stress was studied in male albino rats. Experimental rats (E) were restrained in close-fitting wiremesh cylinders. Control rats (C) were not subjected to restraint. Food and water were made available to C for all the 24 hrs while the E were given them for only 6 hrs daily. The initial lower food intake of E was later reversed to near normal levels. There was a steady fall in the body weights of E, while the C displayed a normal growth rate. Cerebrum, cerebellum, pituitary and adrenals of E weighted significantly more. There was an apparent increase in the weight of thyroid. Gonads displayed no change in weight. The results indicate that chronic restraint causes loss of body weight inspite of a near normal food intake. It also produces an increase in the weight of brain, and certain endocrine organs.

Effect of stress on maternal behaviour.

Primiparous female rats subjected to foot shock and/or immobilization stress were tested for maternal behaviour (MB) by determining the pup retrieval rate (PRR) for 5 minutes. On the third day after parturition PRR significantly decreased when foot shock was given and the fall was more pronounced after immobilization both with and without foot shock. The animals exhibited enhanced MB on the 12th day as compared to the third day, but the stressful situations produced significant decreases in MB qualitatively similar to the third day. By the 20th day when the weaning was in progress the MB decreased to the 3rd day levels. This change in the MB may be due to the changes in the pattern of prolactin secretion during the post partum period.

Effect of stress on behaviour in rats.

The pattern of activity obtained in rats on a regimen of one hour access to food and water was compared to the activity pattern seen when immobilization stress was added to the same regimen. Food and water were provided at the same time of the day. Immobilization stress decreased the body weight, increased the time taken for grooming, maintaining at the same time the food intake. The water intake also increased significantly but the alcohol intake was variable, 3 of the rats showing an increased intake while the rest showed a decreased intake under this stress regimen. The pattern of activity changed from hyper-activity during food restriction alone to increased activity restricted to the first half of the testing time during added immobilization.