Leptin facilitates and inhibits sexual behavior in female hamsters

Wade, George N.; Lempicki, Robin L; Panicker, Anitha K.; Frisbee, R. M.; Blaustein, J. D.

doi:10.1152/ajpregu.1997.272.4.r1354

Cited by 40 publications

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“…In addition, our results confirm the well-known effects of systemic leptin injections on food intake in Syrian hamsters (7,30,39). Leptin injections decrease daily food intake, and yet do not support a conditioned taste aversion in Syrian hamsters (7).…”

Section: Discussionsupporting

confidence: 80%

“…1,14,32,33,41), whereas fewer have examined the appetitive aspects of ingestion, such as the approach to food, the consumption of unpalatable substances, or foraging and hoarding (e.g., [3][4][5][6]11). Treatment with putative anorectic hormones, such as the adipocyte protein leptin, decreases the amount of food eaten in a wide variety of species, including chickens (10,12), mice (9,15,18,26), rats (34), Syrian hamsters (39), ground squirrels (25), dogs (20), sheep (16), primates (36), and marsupials (17). In many species, food deprivation results in decreased plasma concentrations of leptin, increased central release of neuropeptide Y (NPY), and increased food intake relative to that of ad libitum-fed controls (reviewed in Refs.…”

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confidence: 99%

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Food hoarding is increased by food deprivation and decreased by leptin treatment in Syrian hamsters

Buckley

Schneider

2003

American Journal of Physiology-Regulatory, Integrative and Comp

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. Food hoarding is increased by food deprivation and decreased by leptin treatment in Syrian hamsters. Am J Physiol Regul Integr Comp Physiol 285: R1021-R1029, 2003. First published May 1, 2003 10.1152 10. /ajpregu.00488.2002satory increases in food intake are commonly observed after a period of food deprivation in many species, including laboratory rats and mice. Thus it is interesting that Syrian hamsters fail to increase food intake after a period of food deprivation, despite a fall in plasma leptin concentrations similar to those seen in food-deprived rats and mice. In previous laboratory studies, food-deprived Syrian hamsters increased the amount of food hoarded. We hypothesized that leptin treatment during food deprivation would attenuate food-deprivation-induced increases in hoarding. Baseline levels of hoarding were bimodally distributed, with no hamsters showing intermediate levels of hoarding. Both high (HH) and low hoarding (LH) hamsters were included in each experimental group. Fifty-six male hamsters were either food deprived or given ad libitum access to food for 48 h. One-half of each group received intraperitoneal injections of leptin (4 mg/kg) or vehicle every 12 h during the food-deprivation period. Within the HH group, the hoarding score increased significantly in food-deprived but not fed hamsters (P Ͻ 0.05). Leptin treatment significantly decreased hoarding in the food-deprived HH hamsters (P Ͻ 0.05). The LH hamsters did not increase hoarding regardless of whether they were food deprived or had ad libitum access to food. These results are consistent with the idea that HH hamsters respond to energetic challenges at least in part by changing their hoarding behavior and that leptin might be one factor that mediates this response. food intake; hunger; ob protein THE PHYSIOLOGICAL CONTROL of ingestive behavior involves both consummatory and appetitive aspects of behavior, and yet most research has focused only on the consummatory aspect. Most investigators have measured the amount of food ingested in response to treatment with various hormones, neuropeptides, and metabolic conditions (reviewed in Refs. 1,14,32,33,41), whereas fewer have examined the appetitive aspects of ingestion, such as the approach to food, the consumption of unpalatable substances, or foraging and hoarding (e.g., 3-6, 11). Treatment with putative anorectic hormones, such as the adipocyte protein leptin, decreases the amount of food eaten in a wide variety of species, including chickens (10, 12), mice (9, 15, 18, 26), rats (34), Syrian hamsters (39), ground squirrels (25), dogs (20), sheep (16), primates (36), and marsupials (17). In many species, food deprivation results in decreased plasma concentrations of leptin, increased central release of neuropeptide Y (NPY), and increased food intake relative to that of ad libitum-fed controls (reviewed in Refs. 14,32,33,41). This phenomenon is termed postfast hyperphagia and is common in laboratory animals, such as rats, mice, and monkeys and is also observed in most human beings.H...

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Section: Discussionsupporting

confidence: 80%

mentioning

confidence: 99%

Food hoarding is increased by food deprivation and decreased by leptin treatment in Syrian hamsters

Buckley

Schneider

2003

American Journal of Physiology-Regulatory, Integrative and Comp

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“…Although it is known that leptin can accelerate sexual development, there is only one report on the effect of leptin with regard to sexual behavior in female hamsters [20]. Our previous study demonstrated that leptin-treated male rats ejaculated twice as much as aCSF-treated males [1].…”

Section: Discussionmentioning

confidence: 92%

Effects of i.c.v. Administration of Leptin on Copulatory and Ingestive Behavior in STZ-induced Diabetic Male Rats

et al. 2004

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Abstract:It is well known that circulating leptin concentrations correlate with adiposity in both humans and rodents and decrease after fasting, energy restriction, or weight loss. The goal of the present study was to confirm whether the decreases of copulatory behavior and the increases of ingestive behavior in STZ-induced diabetic male rats could be reversed by i.c.v. administration of leptin. Adult male Wistar-Imamichi rats aged 9 weeks were used for the studies. Males received a single injection of STZ (60 mg/kg, i.p.) and vehicle. During the experiment, individual body weight, and food and water intake were measured. The copulatory and ingestive behaviors in STZ-induced diabetic males were observed at 2 and 4 weeks after STZ. At 6 weeks after STZ, leptin (10 µg/10 µl) or aCSF (artificial cerebrospinal fluid) was injected through a lateral ventricle cannula and the above two behaviors were observed again. The i.c.v. leptin injection to STZ-induced diabetic males resulted in a significant increase of ejaculation frequencies (3.6 ± 0.26 vs. 2.9 ± 0.30 times) and a significant decrease in amount of food ingested (36.2 ± 1.93 vs. 23.2 ± 3.76 g), compared with the aCSF-injected control (p<0.01). These findings suggest that the copulatory and ingestive behaviors in i.c.v. leptin-injected STZ diabetic males were restored to levels equivalent to those in control males.

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“…In addition, leptin treatment cannot overcome the suppression of sexual behavior in food-deprived female hamsters (22), and in growth-retarded female rats mating behavior was often absent even after the start of normal cycles (23). At VO we did not observe any sign of first estrous and ovulation in female IUGR rats, in contrast to control rats in which VO was accompanied by estrous and ovulation, shown by vaginal smears and morphologically by corpora lutea in the ovary (24).…”

Section: Discussionmentioning

confidence: 99%

Body Mass Index, Body Composition, and Leptin at Onset of Puberty in Male and Female Rats after Intrauterine Growth Retardation and after Early Postnatal Food Restriction

et al. 2001

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In this study we examined the body composition at onset of puberty in intrauterine growth retarded (IUGR), postnatal food restricted (FR), and control male and female rats. IUGR was induced by ligation of the uterine artery on d 17 of gestation and FR by litter enlargement to 20 pups per mother from d 2 after birth until weaning (d 24). We defined onset of puberty as balanopreputial separation in male rats and vaginal opening in female rats. We calculated body mass index, measured body composition with dual-energy x-ray absorptiometry, and measured leptin concentrations in serum. It was reported previously that early malnutrition, either during late gestation or immediately postnatally, results in a delayed onset of puberty in IUGR and FR male rats and in IUGR female rats, but not in FR female rats. In IUGR male rats at balanopreputial separation and in IUGR female rats at vaginal opening no differences were found in body mass index, body composition, and leptin levels compared with controls. FR male rats had a significantly lower percentage of fat and serum leptin concentrations at balanopreputial separation. FR female rats had a significantly lower body mass index, percentage of fat, and serum leptin concentrations at vaginal opening. We conclude that the onset of puberty in the rat is not dependent on a certain percentage of body fat or a certain threshold of circulating levels of leptin and that food deprivation With limited food supply, animals are forced to set priorities. Shutting off reproductive function during times of food scarcity may be desirable for the survival of a species (1-3). In 1996 Wade et al. (2) noticed that nutritional infertility is particularly observed in females, which is not surprising. A complete reproductive cycle of ovulation, conception, pregnancy, and lactation is one of the most energy-consuming activities that a female mammal can undertake, particularly in species that bear multiple young. In female rats food deprivation simply disrupts the sequential secretion of estradiol and progesterone necessary to induce estrous behavior (2), and reproduction can be resumed when energetic conditions improve. In male rats acute underfeeding stops reproduction by suppressing androgen production and sexual behavior, rather than by suppressing spermatogenesis, as the former could be restored faster than the latter after food supplies are resumed (3). In the studies mentioned above the circumstances of acute malnutrition are discussed. In our study we investigated the consequences of perinatal food deprivation on the process of sexual maturation with respect to body composition and leptin in later life.In an earlier study we showed that prenatal or postnatal malnutrition affects the onset of puberty in both male and female rats. We are aware that the pubertal development starts soon after weaning, but BPS in the male rat and VO in the female rat are the first visual signs during this development. Therefore we used these external signs as measures of onset of puberty, which are commonly used ...

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Leptin facilitates and inhibits sexual behavior in female hamsters

Cited by 40 publications

References 0 publications

Food hoarding is increased by food deprivation and decreased by leptin treatment in Syrian hamsters

Food hoarding is increased by food deprivation and decreased by leptin treatment in Syrian hamsters

Effects of i.c.v. Administration of Leptin on Copulatory and Ingestive Behavior in STZ-induced Diabetic Male Rats

Body Mass Index, Body Composition, and Leptin at Onset of Puberty in Male and Female Rats after Intrauterine Growth Retardation and after Early Postnatal Food Restriction

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