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Biomedical subjects

E del Pozo

Publications and source records attributed to E del Pozo.

67 records · Page 4Linked to original sources
PubMed1978

Inhibitory effect of guanfacine, a central alpha-adrenoceptor agonist, on prolactin secretion stimulated by insulin-induced hypoglycemia.

In six normal male volunteers oral administration of an alpha-receptor agonist, guanfacine (1 mg/q.i.d. for 4 days), had no effect on PRL release induced by 5 mg metoclopramide iv. The same treatment with quanfacine in six other normal subjects significantly reduced PRL secretion stimulated by insulin-induced hypoglycemia (P less than 0.05). These results suggest that an adrenergic pathway, hypothalamic or extrahypothalamic, might be involved in the inhibitory control of PRL secretion.

Adrenergic alpha-Agonists↗
PubMed1976

Lack of effect of acute prolactin suppression on renal water sodium and potassium excretion during sleep.

The possible role of endogenous prolactin (hPRL) in the regulation of renal water, Na and K excretion during sleep was tested in a group of 10 healthy female volunteers. Plasma hPRL and total urinary Na and K excretion were measured at 2- and 4-hourly intervals, respectively, in the control period and after prolactin inhibition with bromocriptin. Despite adequate prolactin suppression, no significant changes were observed in the nyctohemeral excretion rhythms of water, Na and K, suggesting that endogenous prolactin is not instrumental in the control of these parameters.

Adult↗
PubMed1975

Lack of action of prolactin suppression on the regulation of the human menstrual cycle.

Bromocriptin (CB 154) has been found to suppress established lactation at a time when human plasma prolactin (HPRL) concentrations have already returned to the nonpregnant range. This action is due to inhibition of prolactin from the pituitary. It was then thought that a similar degree of inhibition induced during the menstrual cycle may help to uncover other possible biological actions of prolactin. In an attempt to elucidate this question eight breast-feeding mothers and seven normally menstruating volunteers underwent treatment with CB 154, including blood sampling during a sleep period. The dosage was 1 mg., three times daily, for 14 days in the first group and for a whole cycle in the normal volunteers. A control cycle preceded drug administration in the latter group. Prolactin (HPRL), growth hormone (HGH), luteotropin (LH), progesterone (PG), and estradiol (E2) were estimated (mean +/- standard error) along the menstrual cycles in the normal volunteers. HPRL and milk volumes were measured in the breast-feeding women in the base-line period and during treatment. In the postpartum group, basal HPRL had already reached normal levels prior to therapy (10.8 +/- 1.0 ng. per milliliter) and was significantly (p less than 0.002) depressed to 3.7 +/- 0.4 ng. per milliliter by CB 154. This degree of inhibition was effective in suppressing lactation within 24 to 48 hours in all of the subjects in that group. The fall in plasma HPRL from 9.5 +/- 1.5 ng. per milliliter to 3.2 +/- 0.2 ng. per milliliter observed in the normally menstruating women was similar to the one recorded in the breast-feeding group, but the sequence of hormonal changes during the menstrual cycle was not altered by treatment. The overnight study ensured around-the-clock prolactin inhibition. Results indicate no action of prolactin in the regulation of the human menstrual cycle at levels of inhibition at which a biological action of this hormone is clearly suppressed.

Adult↗
PubMed1975

Comparative kinetics of 45Ca and 89Sr in chronic uremic syndrome in the rat.

In rats a chronic uremic syndrome was induced by 5/6 resection and subsequent irradiation of the kidneys. After 5 weeks 45Ca and 89Sr were injected simultaneously, and the different metabolic handling of the two elements was determined applying an open two-compartment model of Calcium kinetics. The uremic animals were compared with two groups of rats which were pairfed, and fed ad libitum, respectively. Besides an elevenfold faster urinary excretion when calculated with Sr, and which was reduced to about one half in the uremic rats, a significant discrimination by bone in favour of Ca was found, with a rather stable factor of 1.2 in the three groups. This is considered to evidence that urinary excretion and bon uptake of Sr are independent processes.

Animals↗
PubMed1975

Suprasellar disturbance in the syndrome of fertile eunuchoidism: case report.

A case of fertile eunuchoidism is presented. The diagnosis was established on the basis of low androgen secretion in the presence of active spermatogenesis, increase in testosterone output after gonadotrophin stimulation, and adequate peripheral response to exogenous testosterone. Resistance to clomiphene stimulation but normal pituitary response to LH-RH was elicited indicating a suprasellar disturbance as the cause of the disorder.

Adult↗
PubMed1975

Pituitary and ovarian response patterns to stimulation in the postpartum and in galactorrhea-amenorrhea. The role of prolactin.

In order to assess the action of prolactin on the puerperal pituitary-ovarian resistance to physiologic stimulation, a study was conducted in 27 women divided into three groups. Group I: 9 postpartum women who did not wish to breastfeed their infants and received 2.5 mg bromocriptin (CB 154) twice daily for 14 days starting immediately after delivery; Group II: 9 normally lactating mothers; and Group III: 9 women with hyperprolactinemia associated with amenorrhea. The three groups underwent stimulation with LHRH and Pergonal 500. Results indicate lack of prolactin dependence in the pituitary-ovarian resistance of the puerperium. The possible mechanisms involved in the anovulatory period of lactation are discussed.

Adult↗
PubMedDate not supplied

Skeletal growth and bone density as sensitive parameters in experimental arthritis: effect of cyclosporin A.

Osteopenia and retarded skeletal growth are consistent features of juvenile polyarthritis. Although the former has also been described in the experimental animal, the consequences of induced joint inflammation on skeletal growth have not yet been documented. In order to investigate the effect of experimental arthritis on these parameters, we studied female rats with adjuvant arthritis (AA) subjected to chronic treatment with cyclosporin A (CsA, Sandimmun). This compound has been found to prevent the development of articular swelling and also repair joint and skeletal lesions in AA rats. Five groups of 8 animals each received oral CsA, 2.5, 5, 10, 20, or 30 mg/kg daily for 30 days. Eight normal and eight diseased, untreated rats served as placebo controls. The parameters studied were (a) measurement of hindpaw swelling, (b) radiometric assessment of vertebral growth, (c) vertebral trabecular density, (d) weight control and nutritional status. At the end of the investigational period, AA-rats on no therapy had severe osteopenia and growth retardation. Treatment with CsA, 2.5 mg/kg, was ineffective, but doses between 5 and 20 mg/kg prevented the development of articular and osseous lesions and normalized growth. A catch-up phenomenon was also observed. The 20 mg/kg dose showed no better effect than 10 mg/kg, and 30 mg/kg produced a significant reduction in bone density and skeletal growth, an effect thought to be toxic in nature. Body weight paralleled growth profiles, and average food consumption was stable in all groups with the exception of somewhat low records in the animals receiving 30 mg/kg.(ABSTRACT TRUNCATED AT 250 WORDS)

Analysis of Variance↗