PubMed Health⌕ Search

Biomedical subjects

S Sakamoto

Publications and source records attributed to S Sakamoto.

At least 19 recordsLinked to original sources
PubMed1979

Prostaglandin F2 alpha metabolite levels in plasma, amniotic fluid, and urine during pregnancy and labor.

Levels of 13, 14-dihydro 15-keto-prostaglandin F2alpha (dhk PGF2alpha) in the plasma of 30 patients as well as in the amniotic fluid of 17 patients, and 5alpha,7alpha-dihydroxy 11-keto tetranor-prostane 1,16-dioic acid (the main urinary metabolite of PGF2alpha [PGF2alpha MUM]) levels in the urine of 30 patients were measured by radioimmunoassay during pregnancy, labor, and the puerperium. During pregnancy, no increase in dhk PGF2alpha (ng/ml) in plasma was detected as the time of delivery approached. The levels of dhk PGF2alpha during the second stage (0.64 +/- 0.15) and also at delivery (0.88 +/- 0.27) were significantly elevated over those in the first stage (0.38 +/- 0.29) (P less than 0.025 and P less than 0.005, respectively). Its level 2 hours after delivery was reduced to predelivery levels. Its levels in umbilical arterial and venous blood were 0.71 +/- 0.26 and 0.67 +/- 0.26, respectively. A significant elevation (P less than 0.01) of dhk PGF2alpha from 0.89 +/- 0.21 before labor to 6.16 +/- 2.40 at delivery was found in amniotic fluid. The hourly excretion of PGF2alpha MUM (microgram/hour) increased significantly from pregnancy levels to 1.06 +/- 0.45 in the first stage (P less than 0.01), to 7.67 +/- 4.31 (P less than 0.005) for the first 2 hours after delivery, and 2.37 +/- 1.08 from 2 to 12 hours after delivery (P less than 0.01). The excretion of PGF2alpha MUM decreased to pregnancy levels 12 hours post partum. These data indicate that during labor the production of PGF2alpha is remarkably increased.

Amniotic Fluid↗
PubMed1979

[The behavior of 7, 12-dimethylbenz(a)anthracene (DMBA)-induced mammary tumors in rats during pregnancy and lactation and hormone levels in the pituitary and plasma (author's transl)].

In order to keep a long-term lactation in primiparous SD strain rats with DMBA-induced mammary tumors, 5 pups aged 5 to 10 days were exchanged every 10 days. FSH, LH and prolactin (PRL) in pituitary tissues and FSH, LH, PRL, estradiol (E2) and progesterone (PRG) in plasma were determined during pregnancy (1,2 and 3-week), at paturition (0 to 12 hours after parturition) and during lactation (1,2,3,4,5 and 6-week). Experimental rats were divided into 6 groups according to the lactating period (non-lactating 3,6,8,12 and 17-week). Blood samples were collected by cardiac puncture 1 hour after an intraperitoneal injection of urethane (150 mg/100 g body weight), and the pituitary gland was removed simultaneously. During pregnancy, plasma PRL was low in the first and second week. PRL, E2 and PRG were high in the third week, during which DMBA-induced mammary tumors began to proliferate. PRG in plasma in the third week was lower than that of the second week. After paturition, the tumors regressed and did not develop for three weeks of lactation, during which plasma PRL was high whereas E2 and PRG were low. The tumors began to proliferate again from the fifth week of lactation, during which E2 was high and the estrous cycle reappeared. The behavior of DMBA-induced mammary tumors in rats during pregnancy and lactation seems to be closely related to plasma estrogen levels.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1979

Morphology and function of isolated hepatocytes transplanted into rat spleen.

Hepatocytes isolated by the collagenase digestive method were transplanted into the spleens of syngeneic rats. Morphology and function of the hepatocytes in the spleen were investigated for 12 to 17 months after transplantation. The transplanted hepatocytes proliferated and reconfigured in the spleen without direct perfusion of portal venous blood and with the presence of an intact host liver. Fourteen to 17 months after transplantation, the hepatocytes which had formed a demarcated nodule occupied approximately 40% of the area of the splenic parenchyma without undifferentiation on microscopic examination. However, the weight of the hepatized spleen did not increase beyond the weight of a normal spleen and the weight of the host liver that had normal morphology also did not differ from a normal liver. Light and electron microscopic studies demonstrated differentiated cord structure and normal architecture for each heptocyte. Furthermore, the hepatized spleen synthesized albumin and glycogen as demonstrated by immunofluorescence and histochemical studies. Ammonia tolerance and indocyanine green clearance tests revealed functioning hepatocytes in the spleen proper. These results indicate that our experimental model lends itself well to investigations in cell growth mechanism and that hepatocellular transplantation has potential clinical application to compensate for impaired hepatic function.

Animals↗
PubMed1979

Effects of adrenergic agonists on the oxygen uptake and amylase output in rat submandibular gland slices.

Oxygen uptake and amylase output in rat submandibular gland slices were measured by utilizing adrenergic agonists. Adrenaline, noradrenaline and isoproterenol significantly stimulated the oxygen uptake and amylase output. In the presence of propranolol or phenoxybenzamine, adrenaline-stimulated oxygen uptake was obviously blocked. Adrenaline-stimulated amylase output was inhibited by propranolol, but was not inhibited by phenoxybenzamine. The increase in oxygen uptake by nornol-stimulated oxygen uptake and amylase output were strongly inhibited by propranolol. The oxygen uptake due to isoproterenol was little affected by phenoxybenzamine. These results suggest that the increase in oxygen uptake seen with adrenergic agonists is mediated by both alpha- and beta-receptors, and that the amylase output is evoked through the stimulation of beta-receptors.

Adrenergic Agonists↗