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Biomedical subjects

M M Hagan

Publications and source records attributed to M M Hagan.

24 records · Page 2Linked to original sources
PubMed1993

Effect of naloxone and antidepressants on hyperphagia produced by peptide YY.

Central injection of peptide YY (PYY) elicits a powerful feeding response with a short latency in satiated rats. Because of this effect, PYY has been implicated as a neurochemical signal in bulimia nervosa. Serotonin agonists and opioid antagonists induce anorectic effects upon feeding behavior in humans and animals. Therefore, to investigate a possible interaction between PYY-induced eating and these anorexigenic agents rats were given injections of either naloxone (100 micrograms/3 microliters, ICV, and 10 mg/kg, SC), fluoxetine (3-30 micrograms/3 microliters and 5-10 mg/kg, IP), or clomipramine (3-30 micrograms/3 microliters and 5-10 mg/kg, IP) prior to fourth ventricular injections of PYY (15 micrograms/18 microliters). Central and peripheral naloxone and IP but not central injections of fluoxetine blocked PYY-induced intake. Clomipramine had no effect. This suggests that PYY-stimulated feeding may require the action of endogenous opioids and may be inhibited by serotonergic function.

Animals↗
PubMed1993

Suppression of peptide YY-induced hyperphagia by terbutaline.

Central administrations of neuropeptide Y and peptide YY (PYY) produce robust increases in food intake, and this response may be contingent upon the availability of insulin. In contrast, beta 2-adrenergic agonists decrease food intake, and this effect also appears to be dependent on circulating insulin. To investigate a possible interaction between PYY and beta 2-adrenergic function, rats were given systemic injections of terbutaline, a beta 2 agonist, at doses of 0, 5, 10, and 50 mg/kg prior to injections of 0.57 nmol PYY in the paraventricular nucleus of the hypothalamus. Terbutaline pretreatment significantly decreased feeding elicited by PYY in a dose-dependent fashion. This suggests that beta 2-adrenoreceptor activity is involved in PYY-induced feeding.

Adrenergic beta-Agonists↗
PubMed1991

An animal model of bulimia nervosa: opioid sensitivity to fasting episodes.

A group of female rats was deprived and maintained at 75-80% of body weight at three different times during development. Following recovery to normal weight, food intake was measured with and without butorphanol tartrate, a kappa-sigma agonist, 8 mg/kg SC. Animals with a history of deprivation (DEP) showed an increase in postrecovery feeding when they were tested at normal body weight and not food deprived. More importantly, butorphanol prolonged food intake in the 3-h eating test only in the rats with a developmental history of food restriction. A developmental history of fasting in eating disorders may trigger changes in opiate systems that result in atypical feeding behavior in the adult.

Animals↗
PubMed1985

The employed uninsured and the role of public policy.

Although most private health insurance is obtained through the workplace, important gaps remain in the present system of employment-related coverage. National survey data reveal that more than 9 million persons with employment experience are uninsured, who, with their uninsured dependents, account for three-quarters of all persons who lack coverage. This paper examines the circumstances and characteristics of the employed uninsured, including their opportunity to secure health insurance fringe benefits, their medical care use and expenditures, and the benefits available in private insurance that is not work related. Alternative public policy responses to the problem of lack of health insurance coverage are also considered.

Adolescent↗