scholarly journals Strain differences in pH-sensitive K+ channel-expressing cells in chemosensory and nonchemosensory brain stem nuclei

2014 ◽  
Vol 117 (8) ◽  
pp. 848-856 ◽  
Author(s):  
Paul F. Martino ◽  
S. Olesiak ◽  
D. Batuuka ◽  
D. Riley ◽  
S. Neumueller ◽  
...  
Keyword(s):  
Brain Stem ◽  
Nucleus Tractus Solitarius ◽  
Ph Sensitive ◽  
Nucleus Ambiguus ◽  
Female Rats ◽  
Brown Norway ◽  
Motor Nucleus ◽  
Male And Female ◽  
Male And Female Rats ◽  
Bötzinger Complex

The ventilatory CO2 chemoreflex is inherently low in inbred Brown Norway (BN) rats compared with other strains, including inbred Dahl salt-sensitive (SS) rats. Since the brain stem expression of various pH-sensitive ion channels may be determinants of the CO2 chemoreflex, we tested the hypothesis that there would be fewer pH-sensitive K+ channel-expressing cells in BN relative to SS rats within brain stem sites associated with respiratory chemoreception, such as the nucleus tractus solitarius (NTS), but not within the pre-Bötzinger complex region, nucleus ambiguus or the hypoglossal motor nucleus. Medullary sections (25 μm) from adult male and female BN and SS rats were stained with primary antibodies targeting TASK-1, Kv1.4, or Kir2.3 K+ channels, and the total (Nissl-stained) and K+ channel immunoreactive (-ir) cells counted. For both male and female rats, the numbers of K+ channel-ir cells within the NTS were reduced in the BN compared with SS rats ( P < 0.05), despite equal numbers of total NTS cells. In contrast, we found few differences in the numbers of K+ channel-ir cells among the strains within the nucleus ambiguus, hypoglossal motor nucleus, or pre-Bötzinger complex regions in both male and female rats. However, there were no predicted functional mutations in each of the K+ channels studied comparing genomic sequences among these strains. Thus we conclude that the relatively selective reductions in pH-sensitive K+ channel-expressing cells in the NTS of male and female BN rats may contribute to their severely blunted ventilatory CO2 chemoreflex.

Substitution of chromosome 1 ameliorates l-NAME hypertension and renal disease in the fawn-hooded hypertensive rat

2005 ◽  
Vol 288 (5) ◽  
pp. F1015-F1022 ◽  
Author(s):  
David L. Mattson ◽  
Mary Pat Kunert ◽  
Richard J. Roman ◽  
Howard J. Jacob ◽  
Allen W. Cowley
Keyword(s):  
Renal Disease ◽  
Genetic Background ◽  
Female Rats ◽  
Chromosome 1 ◽  
Brown Norway ◽  
Male And Female ◽  
Arterial Blood ◽  
Male And Female Rats ◽  
Induced Hypertension ◽  
Excretion Rates

Linkage analysis studies previously identified genetic loci associated with proteinuria and hypertension on chromosome 1 of fawn-hooded hypertensive (FHH) rats. The present studies were performed on conscious male and female rats to evaluate the influence of transfer of chromosome 1 from the Brown Norway (BN) rat to the FHH genetic background (FHH-1BN). Rats were maintained for 2 wk on 8.0% NaCl chow with NG-nitro-l-arginine methyl ester (l-NAME) in the drinking water (12.5 mg/l) to induce hypertension and accelerate the onset of renal disease. Mean arterial blood pressure (MAP) was significantly higher in the male FHH (188 ± 3 mmHg, n = 13) compared with the BN (121 ± 3 mmHg, n = 8); MAP in the FHH-1BN was midway between the two parental strains (167 ± 5 mmHg, n = 9). Urinary protein and albumin excretion rates in the male FHH-1BN (Uprot = 189 ± 36 mg/day, Ualb = 69 ± 16 mg/day, n = 10) were also midway between levels observed in the FHH (Uprot = 485 ± 54 mg/day; Ualb = 206 ± 25 mg/day, n = 13) and the BN (Uprot = 32 ± 5 mg/day, Ualb = 5 ± 1 mg/day, n = 8). Creatinine clearance was elevated, and the degree of glomerular damage was significantly reduced in the FHH-1BN compared with the FHH. Qualitatively similar results were obtained from female FHH, FHH-1BN, and BN rats. The present results indicate that genes contributing to l-NAME-induced hypertension and renal disease are found on chromosome 1 of the FHH rat.

THE PITUITARY AND ADRENAL RESPONSES TO ADMINISTRATION OF OESTRIOL IN GONADECTOMIZED RATS

1961 ◽  
Vol 38 (1) ◽  
pp. 50-58 ◽  
Author(s):  
N. E. Borglin ◽  
L. Bjersing
Keyword(s):  
Pituitary Gland ◽  
Adrenal Cortex ◽  
Clinical Experience ◽  
Uterine Cervix ◽  
Morphological Changes ◽  
Physiological Significance ◽  
Female Rats ◽  
Experimental Conditions ◽  
Male And Female ◽  
Male And Female Rats

ABSTRACT Oestriol (oestra-1,3,5(10)-triene-3,16α,17β-triol) is a weakly oestrogenic substance which, however, in contrast to what was formerly believed, is of physiological significance. Its effect is localized largely to the uterine cervix and vagina. Clinical experience argues both for and against an effect on the pituitary gland. This investigation is concerned with the morphological changes in the pituitary gland and adrenal cortex of gonadectomized male and female rats after the injection of oestriol. It was found that oestriol has the same type of action on these glands as other oestrogens, but under the experimental conditions used, this effect proved much weaker than that produced by oestradiol (oestra-1,3,5(10)-triene-3,17β-diol).

INDUCTION OF GOITRE BY PTU OR KClO4 IN MALE AND FEMALE RATS. EFFECT OF GONADECTOMY

1973 ◽  
Vol 74 (1) ◽  
pp. 88-104 ◽  
Author(s):  
T. Jolín ◽  
M. J. Tarin ◽  
M. D. Garcia
Keyword(s):  
Iodine Content ◽  
High Plasma ◽  
Disc Electrophoresis ◽  
Female Rats ◽  
Male Rats ◽  
Adult Rats ◽  
Male And Female ◽  
Glucose Levels ◽  
Male And Female Rats ◽  
Tsh Levels

ABSTRACT Male and female rats of varying ages were placad on a low iodine diet (LID) plus KClO4 or 6-propyl-2-thiouracil (PTU) or on the same diet supplemented with I (control rats). Goitrogenesis was also induced with LID plus PTU in gonadectomized animals of both sexes. The weight of the control and goitrogen treated animals, and the weight and iodine content of their thyroids were determined, as well as the plasma PBI, TSH, insulin and glucose levels. The pituitary GH-like protein content was assessed by disc electrophoresis on polyacrylamide gels. If goitrogenesis was induced in young rats of both sexes starting with rats of the same age, body weight (B.W.) and pituitary growth hormone (GH) content, it was found that both the males and females developed goitres of the same size. On the contrary, when goitrogenesis was induced in adult animals, it was found that male rats, that had larger B.W. and pituitary GH content than age-paired females, developed larger goitres. However, both male and female rats were in a hypothyroid condition of comparable degree as judged by the thyroidal iodine content and the plasma PBI and TSH levels. When all the data on the PTU or KClO4-treated male and female rats of varying age and B.W. were considered together, it was observed that the weights of the thyroids increased proportionally to B.W. However, a difference in the slope of the regression of the thyroid weight over B.W. was found between male and female rats, due to the fact that adult male rats develop larger goitres than female animals. In addition, in the male rats treated with PTU, gonadectomy decreased the B.W., pituitary content of GH-like protein and, concomitantly, the size of the goitre decreased; an opposite effect was induced by ovariectomy on the female animals. However, when goitrogenesis was induced in weight-paired adult rats of both sexes, the male animals still developed larger goitres than the females. Among all the parameters studied here, the only ones which appeared to bear a consistent relationship with the size of the goitres in rats of different sexes, treated with a given goitrogen, were the rate of body growth and the amount of a pituitary GH-like protein found before the onset of the goitrogen treatment. Moreover, though the pituitary content of the GH-like protein decreased as a consequence of goitrogen treatment, it was still somewhat higher in male that in female animals. The present results suggest that GH may somehow be involved in the mechanism by which male and female rats on goitrogens develop goitres of different sizes, despite equally high plasma TSH levels.

GONADOTROPHIN PATTERNS IN MALE AND FEMALE RATS:

1968 ◽  
Vol 58 (4) ◽  
pp. 600-612 ◽  
Author(s):  
Robert Boyd ◽  
Donald C. Johnson
Keyword(s):  
Ascorbic Acid ◽  
Testosterone Propionate ◽  
Female Rats ◽  
Female Rat ◽  
Feedback Effects ◽  
Male And Female ◽  
Prostate Weight ◽  
Male And Female Rats ◽  
Males And Females ◽  
Normal Males

ABSTRACT The effects of various doses of testosterone propionate (TP) upon the release of luteinizing hormone (LH or ICSH) from the hypophysis of a gonadectomized male or female rat were compared. Prostate weight in hypophysectomized male parabiotic partners was used to evaluate the quantity of circulating LH. Hypophyseal LH was measured by the ovarian ascorbic acid depletion method. Males castrated when 45 days old secreted significantly more LH and had three times the amount of pituitary LH as ovariectomized females. Administration of 25 μg TP daily reduced the amount of LH in the plasma, and increased the amount in the pituitary gland, in both sexes. Treatment with 50 μg caused a further reduction in plasma LH in males, but not in females, while pituitary levels in both were equal to that of their respective controls. LH fell to the same low level in partners of males or females receiving 100 μg TP. When gonadectomized at 39 days, males and females had the same amount of plasma LH, but males had more stored hormone. Pituitary levels were unchanged from controls following treatment with 12.5, 25 or 50 μg TP daily, but plasma values dropped an equal amount in both sexes with the latter two doses. Androgenized males or females, gonadectomized when 39 days old, were very sensitive to the effects of TP and plasma LH was significantly reduced with 12.5 μg daily. Pituitary LH in androgenized males was higher than that of normal males but was reduced to normal by small amounts of TP. The amount of stored LH in androgenized females was not different from that of normal females and it was unchanged by any dose of TP tested. Results are consistent with the conclusion that the male hypothalamic-hypophyseal axis is at least as sensitive as the female axis to the negative feedback effects of TP. Androgenization increases the sensitivity to TP in both males and females.

Studies on progestin binding sites in the hepatic microsomal fraction of male and female rats

1988 ◽  
Vol 117 (4_Suppl) ◽  
pp. S191-S192
Author(s):  
M. STOPPOK ◽  
H. SCHRIEFERS ◽  
E. R. LAX
Keyword(s):  
Binding Sites ◽  
Microsomal Fraction ◽  
Female Rats ◽  
Male And Female ◽  
Male And Female Rats
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