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Biomedical subjects

S Hsiao

Publications and source records attributed to S Hsiao.

At least 37 records · Page 2Linked to original sources
PubMed1984

Effects of cholecystokinin on taste preference and sensitivity in rats.

Cholecystokinin octapeptide (CCK-8) reduced the amount consumed or the number of licks of several concentrations of sucrose in short-term tests with rats that were hungry, satiated, or fed ad lib. The suppressive effect of CCK-8 was generally smaller in the hungry than in the satiated or ad-lib condition. In the satiated and ad-lib conditions, there was no effect of sucrose concentration on the magnitude of the CCK-8 effect. In hungry rats, the concentration-intake function for sucrose was lowered and flattened by both CCK and natural satiety. In order to determine whether a taste change is involved in this short-term reduction of sucrose intake, integrated chorda tympani responses were measured before and after iv infusions of CCK-8 or NaCl. The peak response to 0.3 M sucrose significantly increased after two 5-microgram infusions of CCK-8. Peak and tonic responses to sucrose and saline tended to increase after CCK-8 but not NaCl infusions. These results indicate that CCK-8 reduces sucrose intake in situations in which postingestional factors are minimal and that sucrose concentration has little effect on the size of this suppression. A change in perceived taste intensity or quality may play a role in the inhibitory effect of CCK-8 on intake.

Animals↗
PubMed1983

Analysis of licking responses in rats: effects of cholecystokinin and bombesin.

A detailed analysis of the licking response of rats to milk was made. The effects of cholecystokinin (CCK) and bombesin (BBS) on the consummatory response were compared. The normal licking response pattern was found not to change as the meal progressed; no predictor was found to indicate when the meal would terminate. Licks normally occurred at about six per second, but there were a few licks that occurred at about three per second, with no licking occurring in the intermediate range; thus a distinctive bimodal frequency distribution of the interlick interval was formed. Cholecystokinin was found to reduce the intake of milk and the related licking indexes as expected, but it also induced an unusual licking pattern: The contact duration was shortened, the interlick interval was lengthened, and there was an increase in the proportion of licks with long interlick intervals, the effects that accentuated the bimodality of the distribution of interlick intervals. Bombesin reduced the intake and the related licking indexes as expected; however, it did not induce any unusual licking characteristics as seen with CCK at comparable effective doses. The CCK effect may be mediated partially by a change in the motor aspect of the consummatory response; however, BBS reduced intake by simply decreasing the number of licks and shortening the intake duration.

Animals↗
PubMed1980

Pemoline-induced self-biting in rats and self-mutilation in the deLange syndrome.

Self-mutilation in humans occasionally accompanies physiological disorders such as the deLange syndrome. If pemoline-induced self-biting is behaviorally similar to self-mutilation in the deLange syndrome, similar neurochemical mechanisms may be involved in both. Oral administration of 140 and 220 mg/kg pemoline reliably induced persistent self-biting in rats. This behavior was indistinguishable from stereotyped grooming and its most common target was the medial digits of the foreleg. Pemoline-induced self-biting was accompanied by hyperactivity, stereotyped behavior, abnormal social behavior, abnormal sensorimotor behavior, and unresponsiveness or avoidance of moderate levels of sensory stimuli. Several of these behaviors have also been reported in deLange patients.

Animals↗
PubMed1980

Estrus- and ovariectomy-induced body weight changes: evidence for two estrogenic mechanisms.

Estrogenic modulation of body weight in female rats is usually thought to result indirectly from estrogenic modulation of food intake. The data presented here suggest, however, that estrogens influence body weight by at least two mechanisms, one of which is independent of changes in food intake. When female rats were ovariectomized (Ovx) and food intake was limited to preoperative levels, the Ovx animals nonetheless gained large amounts of body weight. Although Ovx rats gained more weight than controls on the same amount of food, during 33 hr of food deprivation Ovx and control animals lost body weight at the same rate, which indicates that the prefasting metabolic rates of the two groups were generally similar. Examination of recovery from food deprivation suggested that the rate of weight gain after Ovx was very gradual. During the first 40 days after surgery, the ano-nasal lengths of Ovx rats increased twice as fast as the ano-nasal lengths of the intact rats, which suggests a mechanism for the gradual increase in body weight induced by Ovx. The body weights of intact rats followed a regular 4-day cycle during ad lib feeding but when the estrus-associated decrease in food intake was prevented the cyclic body weight changes were dramatically altered. Thus estrogens appear to regulate body weight by at least two mechanisms: modulation of food intake (cycling females) and modulation of ano-nasal growth or other metabolic processes (Ovx females).

Animals↗
PubMed1977

Development of locomotion toward home nesting material in neonatal rats.

Neonatal rats were individually placed in a narrow choice zone between home and fresh nesting materials. At Day 2 postpartum the pups made significantly more home-choosing responses (vs responses for fresh nesting material). At a mean of 5.6 days (range, 4 to 9 days) the pups reached a criterion of 2 consecutive days of responses all for home nesting material. The number of head contacts increased abruptly upon reaching the criterion. In a 2nd experiment we observed that the pups which were repeatedly tested performed no better than those which were tested for the 1st or the 2nd time. Thus, (a) home-seeking responses appear to emerge substantially earlier than previously reported by other investigators, (b) head-contact responses appear to be related to successful home-chossing, and (c) some maturational rather than experiential factors are important for the development of both head-contact and home-choosing responses.

Aging↗
PubMed1977

Specificity of cholecystokinin satiety effect: reduction of food but not water intake.

The C-terminal octapeptide of cholecystokinin (CCK) was injected into water-deprived rats to observe the effect on water and milk intake. The doses used were 0, 20, and 40 Ivy dog units/kg. The data indicated that milk intake was suppressed in a dose-related fashion within 2-4 min of injection but water intake was not suppressed. This satiety hormone is thus specific to food intake.

Analysis of Variance↗