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3.
Kingston; s.n; Oct. 1984. 224 p. ills, tab.
Tese em Inglês | MedCarib | ID: med-13632

RESUMO

In recent years interest has mounted concerning the role of marihuana on reproductive physiology. Various reports in the literature suggest that marihuana influences female reproduction, and pose significant risks for the offspring. It has also been blamed for its embryotoxic/foetotoxic and teratogenic manifestations in animals. These reports are conflicting, confusing and sometimes contradictory. However, it could be conceived that marihuana use induces reproductive hazard. Moreover, marihuana has been used for facilitating childbirth and was tried in the management of menstrual disorders, but there is no evidence to establish the scientific basis for such claims. Despite the widespread use of marihuana, there are only a few studies available describing the effects of this drug in the female. This study was designed to investigate the potential effects of marihuana smoking on female reproductive process and foetal development. Albino rats were utilized for this experiment due to various practical advantages like availability, low cost, large number of animals per litter and brief gestational periods. Marihuana smoking has been employed to mimic human use and to restrict the use of heavy doses. Uterine smooth muscle contractility was studied to determine the influence of marihuana extract and the consequences of smoke exposure on uterine contractility. A chronic study, i.e. follow-up through two generations, was carried out since acute effects of marihuana may be insignificant and since continous maternal exposure could damage the foetus and chronic use could further deleterious effects. During this study a close watch was kept on the body weight to rule out the possible influence of undernutrition which may affect the reproductive function. Marihuana smoking has resulted in the reduction of body weight within the first week, but these animals later demonstrated a positive gain in weight and did not exhibit any obvious signs of undernutrition which may affect the reproductive function. Marihuana smoking has resulted in the reduction of body weight within the first week, but these animals later demonstrated a positive gain in weight and did not exhibit any obvious signs of undernutrition. A positive gain in body weight suggests development of tolerance following the smoking exposure. All the marihuana smoke-exposed rats exhibited delayed onset of oestrous activity but frequent oestrous cycles with a reduction in the duration of oestrous period. Such a change could interfere with fertility rate. Smoking also has resulted in suppression of ovalution. The fertility index (number of pregnant females/number of mated females) was significantly lowered. Other observations were shortened gestation period, low birth weight and diminished litter size. Reduction in fertility index and the gestation period may be the consequence of uterine stimulatory action of marihuana or suppressed ovarian activity. Low birth weight and reduction in the litter size could be due to probable embryotoxic effects of interference with transport mechanisms. Uterine contractile responses produced by crude aqueous marihuana extract (CAME) were significantly higher in smoke-exposed rats. CAME seems to depolarize the uterine smooth muscle, by activiting the muscarinic receptors. Chronic exposure to marihuana smoke seems to alter this response at receptor level. CAME is shown to possess both contractile and relaxing properties with dominant activity of the former. Chronic exposure to marihuana smoke resulted in appearance of tumours, like serous cystomata, follicular cysts, telengiectatic cysts, adenofibroma and adenocarcinoma in 50 percent of the experimental animals. The significance of this uterine stimulatory and tumorigenic potential of marihuana may have far-reaching consequences due to interference with foetal blood flow. Such a situation couls lead to deficient transport of O2, nutrients and toxic metabolities and precipitate not only foetal underdevelopment, but also reduction in litter size. Use of marihuana seems to influence the reproductive activity in females as evidences by delayed onset of oestrous activity, frequent oestrous cycles with reduced fertility index, shortened gestation periods, increased litter mortality, low birth weight, etc. This study clearly indicates that the marihuana smoke not only affects the maternal well-being but also jeopardizes the conditions under which the foetuses grow and develop (AU)


Assuntos
Gravidez , Ratos , Feminino , Fumar Maconha/efeitos adversos , Reprodução/efeitos dos fármacos , Desenvolvimento Embrionário e Fetal/efeitos dos fármacos , Contração Uterina/efeitos dos fármacos , Músculo Liso/efeitos dos fármacos , Alterações do Peso Corporal , Ovulação/efeitos dos fármacos , Fertilidade/efeitos dos fármacos , Seguimentos
7.
Kingston; s.n; Jan. 1978. 87 p. ills, tab.
Tese em Inglês | MedCarib | ID: med-13711

RESUMO

Little is known of the effects of malnutrition on the composition of adipose tissue in children. Total body fat is severely depleted in most cases but it is not known how this affects the structure and subsequent regeneration and metabolic activity of the tissue. There is evidence that during normal growth in both children and animals that there are sensitive periods during which the cell number and cell size in adipose tissue may be altered by nutritional factors. This study was designed first to develop methodology for use in the analysis of small samples of tissues and then to study the composition of adipose tissue of rats which had been malnourished and then refed with high fat diets. Two different fats, peanut oil and coconut oil were used in order to investigate whether the type of fat in the diet infleunced the tissue composition. The available literature has been reviewed and the results of the measurement of DNA, protein and fat content of the tissue, of total body fat and of total body water are presented. The study has shown that: (a) adipose tissue of rats fed a protein-free diet containing peanut oil was more depleted of fat than if the diet contained coconut oil; (b) the accumulation of fat in the tissue of malnourished rats which had been refed with a diet containing peanut oil was more rapid than in those which were fed coconut oil. The increase in adipose tissue mass in both cases occurred by an increase in cell size rather than cell number; (c) total body water and total body fat were lower than normal in the malnourished rats. There was a progressive increase in total body fat as refeeding continued. Total body water increased very rapidly in the early stages of refeeding with peanut oil. Greater than normal values were attained only after 4 days refeeding. These values thereafter declined to normal. There was a slower increase to normal in the rats fed coconut oil. Total body fat was measured in children recovering from malnutrition on high energy diets containing either peanut oil or coconut oil. There was a tendency for the total body fat to increase more slowly in those fed coconut oil (Summary)


Assuntos
Humanos , Criança , Ratos , Lipídeos/metabolismo , Gorduras Insaturadas na Dieta/metabolismo , Desnutrição Proteico-Calórica/metabolismo , Água Corporal , Tecido Adiposo/metabolismo , Alterações do Peso Corporal , Pregas Cutâneas
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