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Biomedical subjects

A Goldraij

Publications and source records attributed to A Goldraij.

At least 37 records · Page 2Linked to original sources
PubMed1991

Influence of gonadic hormones on the rat submaxillary gland.

The area of the granular tubules of the submaxillary gland was evaluated in male and female rats at 60 days of age. In males, this area was significantly greater than in females, corroborating the presence of sex dimorphism in this structure. Dimorphism disappeared after castration. Testosterone increased tubular area. Estrogen and progesterone as well as pregnancy reduced it. The tubular surface was significantly greater at term than at mid pregnancy.

Animals↗
PubMed1991

Spontaneous activity in vitro of the uterine horns of unilaterally pregnant rats. Relations with glycogen and triglycerides levels.

Effects of the placental implantation on the in vitro spontaneous contractile activity of uterine strips incubated in a glucose-free KRB medium, and its relationship with the glycogen and triglycerides tissue levels, have been analysed using unilaterally pregnant rats. The spontaneous activity increased with pregnancy duration, both in the implantation zone (Impl) and the interembryonic segment (Inter) of the pregnant horn. It increased in the contralateral sterile horn (SH) also. Activity was significantly greater in SH and Inter than in Impl, at the same stage of pregnancy. Uterine glycogen, but not triglycerides, appeared to be the substrate used to sustain contractile activity, as its concentration was greater in Impl, the relatively quiescent zone.

Animals↗
PubMed1990

Effect of partial starvation on in vitro spontaneous activity and glycogen levels of uterine smooth muscle from pregnant and non pregnant rats.

Effects of a restricted-diet (50% of the normal feeding) given during 14 days, on the isometric developed tension (IDT) of uterine horns isolated from pregnant and non pregnant (diestrous) rats, incubated in a KRB-medium without glucose, were explored. In 14 days-pregnant rats, dietary restriction did not alter the contractile activity with respect to normal-fed controls. Besides, levels of uterine glycogen, immediately after killing the animals or after 60 min incubation, remained unaltered. In advanced pregnancy partial starvation led to decay of spontaneous contractile activity after 60 min incubation. However, the considerable increment in the levels of tissue glycogen at 0 time was not modified, nor its decrease at the end of the in vivo experimental period. In non-pregnant rats, a reduced feeding did not alter the development of contractile tension, but exerted a pronounced effect on the glycogen levels: these were significantly lower than controls at 0 time but suffered no changes after 60 min on in vitro activity. Indomethacin appeared to have no effect on the spontaneous contractile activity of 14 days-pregnant rats. It significantly depressed contractility in 21 days-pregnant rats. Indomethacin did not modify the levels of glycogen in any of the experimental groups.

Animals↗
PubMed1990

[Sexual dimorphism in rat submaxillary gland].

The existence of sexual dimorphism (SDM) in tubules and acini of the submaxillary gland was investigated in male and female 60 day-old Wistar rats. Conventional histology was followed by evaluation of 1) Percentage of area occupied by tubules, acini, and other tissues and 2) Tubular area, employing a semi-automatic image analyser. The granular tubules of male rats were larger than those of females. This statistically significant difference indicates the existence of SDM from a morphological viewpoint. Castration seems to abolish these differences by inducing involution of tubular tissue in males. Whereas treatment with testosterone seems to reconstitute tubular tissue in castrated males, a similar dose of estradiol benzoate elicits a reduction in tubular size in ovariectomized females.

Animals↗
PubMed1989

Effect of dietary restriction on triglyceride levels in the uterus isolated from pregnant rats. Influences of prostaglandins and indomethacin.

Triglyceride (TGs) concentrations in uterine strips isolated from 14 or from 21 days-pregnant rats, either normal-fed or following a restricted-diet rats (50% food intake for 14 days), were measured. Determinations were made immediately after killing (0 min time or post-isolation) as well as after a period of incubation in glucose-free medium (60 min time or post-incubation). The post-isolation levels of TGs (0 min) in the uterus from normal-fed animals at 14 or at 21 days of pregnancy, were significantly higher in implantation sites than in the interembryonic segments. These values of TGs (0 time) did not change, in comparison to post-incubation concentrations (60 min), either without additions or in the presence of indomethacin (5 X 10(-6) M) or of prostaglandins (PGs) E1, E2 or F2 alpha (10(-7) M). At 0 time, uterine TGs of rats subjected to dietary restriction, increased as pregnancy progressed, more than in normal-fed controls. The post-incubation (60 min) pattern was different depending on the days of pregnancy; i.e. at 14 days, incubation in Krebs-Ringer Bicarbonate-medium (KRB) led to a significant fall unaffected by the addition of propranolol (10(-6) M). However, in the presence of indomethacin, TGs values had a level similar to the initial one (0 time). Furthermore, exogenous PGE1 or PGE2 failed to alter the effect of indomethacin, as PGF2 alpha did.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenergic alpha-Antagonists↗
PubMed1989

Effects of a restricted diet on the submaxillary gland of intact and castrated male rats.

Effects of diet restriction (50% of normal) during 4 weeks were studied in intact (controls) and castrated rats. A restricted diet led to cessation of animal growth. No differences were observed between controls and castrated rats. However, underfeeding produced a reduction of testicular weight in intact rats. Histochemical observations showed a reduction of tryptophan (a marker of the presence of testosterone-dependent protein) in the submaxillary gland from animals fed a restricted-diet. In animals fed a normal diet, castration reduced significantly the gland weight, as well as the diameter of tubules and acini. When animals fed a restricted-diet are compared, no significant differences were found in the diameter of tubules and acini or in the weight of submaxillary glands.

Animals↗
PubMed1987

Prostaglandin output from and the spontaneous inotropism of uterine horns isolated from underfed rats at different stages of the sex cycle. Smooth muscle contractile influences of indomethacin and of methoxamine.

The influences of a period of 15 days of restricted diet (50% of the normal food intake) in rats sacrificed at different stages of the sex cycle (proestrus, estrus, metestrus and diestrus), were explored on: (1) the magnitude of uterine spontaneous phasic contractions (isometric developed tension = IDT); (2) the release of prostaglandins (PGs) F2 alpha and E2; from the uterus and (3) the myometrial inotropic responses evoked by methoxamine and indomethacin. At estrus and at proestrus, preparations from restricted diet rats exhibited greater initial (post-isolation) IDT and better contractile constancy during 60 min than did uteri from normal fed rats. This enhanced contractile constancy, but not that of preparations from control fed rats, was prevented by incubation "in vitro" with indomethacin (10(-6) M). At metestrus and at diestrus, uteri from normal fed rats presented higher initial levels of IDT and even more sustained contractile constancy than at estrus or at proestrus. Moreover, contractile profiles remained unaltered following the dietary restriction and the presence of indomethacin evoked similar negative inotropic actions in both experimental groups (fed and underfed). Dose-response curves for methoxamine documented its positive, but different, inotropic actions in the two groups and at the four periods of the estrous cycle. Indeed, in the underfed group at estrus and at proestrus, dose-response curves for methoxamine were shifted to the left of those in fed controls, a situation prevented by indomethacin (10(-6) M); whereas at metestrus and at diestrus, no differences in the inotropic reactivity towards methoxamine between the two experimental groups, were detected. On the other hand, indomethacin shifted to the right dose-response curves for the agonist, both in preparations from normal fed and from restricted diet rats. The generation and release of PGF2 alpha and of PGE2 were explored under normal and restricted diet conditions, both at estrus and at diestrus. Following the dietary restriction, the output of PGE2 from estrous uteri was augmented in comparison to controls, whilst the release of PGF2 alpha was not affected. At diestrus, dietary restriction failed to alter the uterine output of either one of these PGs. Results suggest that a greater generation and release of PGE2, following underfeeding, appears to subserve the increased spontaneous motility and the greater sensitivity of the rat uterus for adrenoreceptor agonists.

Animals↗
PubMed1987

Triglycerides in isolated rat uterine strips. Influences of glucose deprivation, 2-deoxy-D-glucose, estrogens and exogenous or endogenous prostaglandins E1, E2 and F2 alpha.

Triglyceride (TG) levels in uterine strips isolated from natural estrous, ovariectomized or ovariectomized, estradiol-injected rats, were explored. Determinations were performed either immediately after isolation (initial or 0 time) as well as after one hour period of incubation (60 min time) in glucose containing or in glucose-free solution. The influences of indomethacin alone (5 X 10(-6) M) or of indomethacin plus prostaglandins (PGs) E2, E1 or F2 alpha (10(-7) M). delivered in vitro at the beginning of the incubation, and of 2-deoxy-D-glucose (2-DG) at 11.0 mM, were also studied. Ovariectomized animals (25 days); estrous animals or spayed 17-beta estradiol-injected animals (0.5 microgram + 1.0 microgram, 24 hours prior to sacrifice), were employed. At 60 min time in glucose-free medium, but not in glucose containing solution, triglycerides declined significantly in strips from spayed rats, the diminution being prevented by in vitro indomethacin. The presence of exogenous PGF2 alpha or of PGE1, but not that of PGE2, abolished the preventive effect of indomethacin. Initial TG levels in spayed uteri treated with estradiol were significantly smaller that in untreated controls. However, under these conditions, indomethacin alone or indomethacin plus the tested PGs, had no action, the same being evident at natural estrus. In strips from spayed rats and incubated in the absence of glucose but with the presence of 2-DG, the effects of indomethacin and of indomethacin plus exogenous PGs on tissue TG levels were similar, although more evident, than in the sole absence of extracellular glucose. Moreover, TG levels in uterine strips obtained from ovariectomized rats injected with 17-beta estradiol and incubated for 60 min in glucose-free medium plus 2-DG, were smaller than immediately after isolation (0 time), the decrement being prevented by indomethacin, not affected by PGE2 and abolished by PGE1 or by PGF2 alpha. The foregoing results suggest that the diminution of TG in uterine strips incubated in the absence of glucose could be due to a greater metabolic utilization of neutral fats, a phenomenon possibly associated to the lack of exogenous substrate. Moreover, this decrement of tissue TG appears to be linked to the influence of certain PGs and of estrogens, for in ovariectomized, but not in estrous or in spayed-estrogenized conditions, indomethacin prevented the TG decrement in glucose-free solution, whereas PGs E1 and PGF2 alpha abolished the preventive action of indomethacin.(ABSTRACT TRUNCATED AT 400 WORDS)

Alprostadil↗
PubMed1987

Tolbutamide in vitro diminishes spontaneous and oxytocin-induced contractions of uterine smooth muscle from diestrous rats.

The in vitro spontaneous isometric-developed tension (IDT) of uterine horns obtained from diestrous rats exhibited, after 60 min of post-isolation activity, a clear decrease in magnitude, averaging 18.2 +/- 5.2%. In presence of tolbutamide, a concentration-dependent decrease of IDT, significantly greater than the spontaneous reduction (75.1 +/- 5.4%, with tolbutamide at 10(-4) M), was observed. Incubation with propranolol (10(-6) M) or with sotalol (10(-4) M) failed to alter the negative inotropism evoked by tolbutamide. On the other hand, the sulfonylurea (10(-4) M) shifted most points of the dose-response curve to the right for the contractile stimulation elicited by oxytocin, an influence not altered by the simultaneous presence of propranolol or sotalol. Tolbutamide failed to influence the negative inotropic dose-response curve for isoproterenol and did not modify the decrease in contractions evoked by theophylline (10(-4) M). It was also found that tolbutamide was devoid of action on the basal release of prostaglandin E2 from uterine strips and on the positive inotropic dose-response curve for added PGE2 or PGF2 alpha, constructed in presence of indomethacin (5 X 10(-6) M). The present findings do not permit a simple explanation regarding possible factors underlying the negative uterine inotropic influence of tolbutamide in the rat uterus. However, it appears that alterations in the integrity of tissue excitability and contractile apparatus, adrenergic implications, changes in uterine cAMP levels, inhibition of cyclo-oxygenase or low PEG2 synthesis and release, are not plausible mechanisms to explain the negative inotropism of tolbutamide. Therefore, it is suggested that the contractile depression evoked by tolbutamide and its action on the contractile effect of oxytocin might be linked to the impaired synthesis of other prostanoids, namely PGF2 alpha, PGI2 or PGD2, although the participation of not yet determined factor(s), namely changes in Ca2+ ion movements, cannot be discarded.

Animals↗
PubMed1985

Different effects of prostaglandins E2 and F2 alpha on triglyceride levels in uterine smooth muscle from diabetic diestrous rats.

Triglyceride (TG) concentrations in uterine strips isolated from diestrous normal rats, from diestrous streptozotocin (single iv. injection of 65 mg X Kg body weight-1)-diabetic rats and from diestrous diabetic animals, treated in vivo with insulin (protamine zinc insulin 4U X day-1, 6 days, sc.), were measured. Determinations were made immediately following killing (0 min, or postisolation) as well as after an incubation period in glucose-free medium (60 min, or postincubation), with or without additions. The basal or postisolation levels of TGs (0 min) in the uterus from control normal rats (TGs: 17.0 +/- 0.5 mumol X g-1, d.w.; blood glucose: 100.4 +/- 4.8 mg X dl-1) were lower (P less than 0.001) than in streptozotocin-diabetics (TGs: 28.5 +/- 0.6 mumol X g-1, d.w.; blood glucose: 302.0 +/- 10.1 mg X dl-1) and the treatment with insulin (blood glucose: 165.0 +/- 14.7 mg X dl-1), restored TGs towards normal (19.3 +/- 1.3 mumol X g-1, d.w.). The postisolation levels of TGs (0 min) in the uterus from normal controls did not differ in comparison with postincubation values (60 min), either without additions or in presence of indomethacin (5 X 10(-6)M) or of prostaglandins (PGs) E2 or F2 alpha, at 10(-9)M. On the contrary, in uteri from diabetic animals, the higher initial TG levels diminished spontaneously in comparison to controls (P less than 0.001) following 60 min of incubation without additions; this decrement being antagonized by indomethacin or by propranolol (10(-6)M). Moreover, exogenous PGE2 failed to alter the effect of indomethacin, whereas PGF2 alpha evoked its abolition. In addition, propranolol, which effectively blocked the spontaneous decrement of TGs as did indomethacin, prevented also the influence of PGF2 alpha on the action of the cyclo-oxygenase inhibitor. In the case of uteri from diabetic rats treated in vivo with insulin, TG levels remained unaltered at the end of an incubating period of 60 min without additions and so they did following the administration of indomethacin or PGF2 alpha. The results document that the regulation of TGs in the diestrous rat uteri, suspended in glucose-free solution, is affected differently by PGE2 and F2 alpha, depending on the existence or not of an untreated diabetic condition. They also suggest that the action of PGF2 alpha may involve the activation of tissue beta-adrenoreceptors.

Animals↗
PubMed1984

Prostaglandin E2 and prostaglandin F2 regulation of triglyceride levels in uterine smooth muscle from restricted-diet estrous and diestrous rats.

Triglyceride concentrations in uterine strips isolated from estrous and diestrous normal-fed or restricted-diet (50% food intake for 15 days) rats, were measured. Determinations were made immediately following killing (0 min, or postisolation) as well as after a period in glucose-free medium, (60 min or post-incubation) with or without additions. The postisolation levels of triglycerides (0 min) in the uterus from normal-fed estrous animals were lower than in diestrus but in each group did not differ in comparison with postincubation values (60 min), either without additions or in the presence of indomethacin (10-6M). Initial (0 min) tissue triglycerides of estrous and diestrous partially-starved rats were significantly higher than in their respective fed controls and exhibited different modifications depending on the stage of the sex cycle. In estrus, levels remained unaltered at the end of an incubating period without additions and declined in the presence of indomethacin. This influence of indomethacin was not modified by added PGF2 (10(-9)M) but was effectively abolished by PGE2 (10(-9)M). On the contrary, in diestrus, initial triglyceride levels diminished spontaneously following 60 min without additions, this being antagonized by indomethacin or propranolol (10(-6)M). Furthermore, exogenous PGE2 failed to alter the effect of indomethacin whereas PGF2 evoked its abolition. Propranolol, which effectively blocked the spontaneous decrement of triglycerides as did indomethacin, prevented also the influence of PGF2 on the action of indomethacin. The foregoing results are compatible with the notion that the regulation of triglycerides in rat uteri suspended in the absence of exogenous substrate, is affected differently by prostaglandin E2 and F2 alpha depending on the state of the sex cycle. They also suggest that the phenomenon may involve the activation of the beta adrenoreceptors.

Animals↗
PubMed1983

In vitro contractile responses of the uterus from 'restricted diet' rats to adrenoceptor agonists. Influence of cyclo-oxygenase inhibitors.

The experiments concerned the effects of 15 days of restricted diet (50% of the normal food intake) on the magnitude of phasic contractions (Isometric Developed Tension, IDT) of uterine horns isolated from estrous rats. During 60 min following isolation, the IDT of normally fed controls diminished significantly whereas preparations from animals on the restricted diet had a better contractile constancy. This improved motility was prevented by blockers of prostaglandin (PG) synthesis as well as by return to a normal diet. Cumulative dose-response curves for isoproterenol, norepinephrine and methoxamine were made for the different groups. Isoproterenol and norepinephrine evoked a dose-dependent inhibition of IDT. This response was significantly shifted to the right with uteri from restricted diet animals. Following incubation with propranolol, norepinephrine stimulated the magnitude of contractions significantly more in uterine horns from restricted diet rats than in those from controls. The dose-response curve showing the enhancement of motility induced by methoxamine was displaced to the left in preparations from animals on a restricted diet. This shift was abolished by restoring the normal diet as well as by the presence in vitro of indomethacin or acetylsalicylic acid. The results suggest that tissue PGS, the prevalence of alpha-adrenoceptor mechanisms and the reduction of beta-ones, are involved in the contractile behavior of the uterus isolated from restricted diet rats.

Animal Feed↗
PubMed1983

Partial starvation, and "in vitro" contractions of rat uterine smooth muscle. Levels of glycogen and triglycerides.

The effects of a restricted-diet (50% of the normal intake during 25 days) on the isometric developed tension (IDT) of uterine horns isolated from diestrous non-cycling rats, were explored. After 60 minutes following isolation and mounting the IDT of controls suspended in glucose containing solution was higher than in preparations from underfed animals but this was no the case in the absence of glucose. Glycogen levels of controls at 60 minutes were smaller in substrate-free than in the presence of glucose whereas no change was detected in horns from restricted-diet rats. Preparations from underfed animals had a significantly augmented basal concentration of triglycerides which diminished at 60 minutes following the removal of glucose from the suspending solution. This effect was abolished by the addition of 3-O-methyl glucose and by blockers of beta-adrenoreceptors such as propranolol or MJ-1999. A similar situation occurs when the animals were injected prior killing with 6-hydroxydopamine.

3-O-Methylglucose↗
PubMed1983

Dietary restriction alters the "in vitro" spontaneous or oxytocin-induced contractions of uterine smooth muscle from estrous rats. Possible participation of prostaglandins.

Rats subjected to a restricted-diet (50% of the normal intake for 15 days) presented a progressive reduction of body weight. The isometric developed tension (IDT) of uterine horns obtained from these animals during estrus exhibited greater initial (postisolation) values and a better constancy with time than preparations from normal-fed controls. The enhanced contractions were diminished after a refeeding period of 6 days as well as following the addition into the suspending medium of inhibitors of cyclo-oxygenase (indomethacin or acetylsalicylic acid). Cumulative dose-response curves to oxytocin documented a greater sensitivity in uterine horns from restricted-diet rats than in those from controls or refed animals. The output of prostaglandin (PG) E2 but not that of PGF2 alpha into the external solution was significantly higher (P less than 0.001) in the case of uterine tissue from restricted-diet rats than in normal fed controls. The findings suggest that changes in IDT evoked by partial starvation are associated with the enhanced generation of some PGs by the uterus.

Animals↗