Sodium dependence of high affinity glutamic acid transport in cortical synaptosomes?a comparison of Long-Evans and Sprague-Dawley rats

1981 ◽  
Vol 6 (2) ◽  
pp. 149-164 ◽  
Author(s):  
D. D. Wheeler
Keyword(s):  
Glutamic Acid ◽  
Acid Transport ◽  
Sprague Dawley ◽  
Sodium Dependence ◽  
High Affinity ◽  
Sprague Dawley Rats ◽  
Long Evans

Ultrastructural Investigation of Spontaneous Pituitary Adenomas in Aging Sprague-Dawley Rats

1982 ◽  
Vol 40 ◽  
pp. 216-217
Author(s):  
D. J. McComb ◽  
J. Beri ◽  
F. Zak ◽  
K. Kovacs
Keyword(s):  
Microscopic Study ◽  
Pituitary Adenomas ◽  
Wistar Rats ◽  
Microscopic Level ◽  
Sprague Dawley ◽  
Prolactin Cells ◽  
Light Microscopic Level ◽  
Ultrastructural Investigation ◽  
Sprague Dawley Rats ◽  
Long Evans

Investigation of the spontaneous pituitary adenomas in rat have been limited mainly to light microscopic study. Furth et al. (1973) described them as chromophobic, secreting prolactin. Kovacs et al. (1977) in an ul trastructural investigation of adenomas of old female Long-Evans rats, found that they were composed of prolactin cells. Berkvens et al. (1980) using immunocytochemistry at the light microscopic level, demonstrated that some spontaneous tumors of old Wistar rats could contain GH, TSH or ACTH as well as PRL.

Characterization of vasoactive intestinal peptide receptors on rat alveolar macrophages

1994 ◽  
Vol 267 (3) ◽  
pp. L256-L262 ◽  
Author(s):  
H. Sakakibara ◽  
K. Shima ◽  
S. I. Said
Keyword(s):  
Vasoactive Intestinal Peptide ◽  
Alveolar Macrophages ◽  
Inflammatory Responses ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
High Capacity ◽  
Sprague Dawley ◽  
Major Band ◽  
High Affinity ◽  
Sprague Dawley Rats

In view of the evidence that vasoactive intestinal peptide (VIP) may modulate acute inflammatory injury in the lung, we investigated the presence and characteristics of VIP receptors on alveolar macrophages (AMs). We examined the binding of monoiodinated [Tyr(125I)10]-labeled VIP (125I-VIP) to rat AMs (> 96% pure), obtained from Sprague-Dawley rats by bronchoalveolar lavage (BAL). At 23 degrees C, the interaction of 125I-VIP with AMs was rapid, reversible, saturable, and linearly proportional to the number of cells. At equilibrium, the binding was competitively inhibited by 10(-11)-10(-6) M of native peptide [half-maximal inhibition (IC50) = 0.53 +/- 0.34 nM, n = 8], with evidence for two classes of binding sites: one with a high affinity (Kd = 0.20 +/- 0.09 nM) and a low capacity (1,190 +/- 640 sites/cell) and another with a low affinity (Kd = 43.2 +/- 13.8 nM) and a high capacity (51,700 +/- 14,000 sites/cell). VIP-related peptides inhibited the binding with the order of potency: VIP > peptide histidine isoleucine > helodermin >> secretin; glucagon was ineffective. In the presence of 3-isobutyl-1-methylxanthine, VIP dose dependently stimulated adenosine 3',5'-cyclic monophosphate accumulation in intact AMs, with maximal stimulation (6.3 times basal level) at 1 nM, and half-maximal accumulation at 0.23 +/- 0.11 nM VIP (Kd for high-affinity sites). For determination of the mass of the VIP receptor, 125I-VIP was covalently bound to AMs with the cross-linking agent dithiobis succinimidyl propionate. Autoradiographic studies after sodium dodecyl sulfate/polyacrylamide gel electrophoresis of solubilized affinity-labeled cells revealed a single major band of M(r) 76,400. We conclude that VIP binds to specific receptors on rat AMs that are coupled to adenylate cyclase, through which VIP may modulate inflammatory responses within the lung.

Ontogeny of glycine transport in isolated rat renal tubules

1977 ◽  
Vol 233 (3) ◽  
pp. F241-F246
Author(s):  
K. S. Roth ◽  
S. M. Hwang ◽  
J. W. London ◽  
S. Segal
Keyword(s):  
Rat Kidney ◽  
Renal Tubules ◽  
Sprague Dawley ◽  
Entry Rate ◽  
Glycine Uptake ◽  
Adult Rat ◽  
High Affinity ◽  
Sprague Dawley Rats ◽  
Rate Kinetics ◽  
Isolated Renal Tubule

Isolated renal tubule preparations were made from newborn Sprague-Dawley rats and used to study initial entry rate kinetics of glycine. The results were compared to those obtained in the isolated tubule preparation from the adult rat kidney. While initial rates of glycine uptake were identical for newborn and adult tubules, significant differences in influx kinetics were demonstrated. Of the two apparent transport Km systems shown to be present in the newborn tubule, the high-affinity, low-capacity system accounts for about 40% of total glycine uptake at physiologic concentrations. The high-affinity, low-capacity system of the adult tissue accounts for about 10% of total uptake at the same concentration range. The data lend strength to the argument against the concept that the physiologic hyperglycinuria of the newborn rat is due to either impaired ability to concentrate glycine intracellularly or to absence of one or more transport mechanisms for glycine.

Oxytocin resistance in Brattleboro rat adipocytes and comparative studies on insulin or oxytocin responsiveness in normal rat adipocytes

1983 ◽  
Vol 61 (11) ◽  
pp. 1418-1425 ◽  
Author(s):  
K. Hanif ◽  
H. J. Goren ◽  
R. M. Geonzon ◽  
K. Lederis ◽  
M. D. Hollenberg
Keyword(s):  
Calcium Concentration ◽  
Maximal Response ◽  
Sprague Dawley ◽  
Assay Medium ◽  
Rat Adipocytes ◽  
Sprague Dawley Rats ◽  
Normal Rat ◽  
Increased Sensitivity ◽  
Long Evans ◽  
Treatment Use

We have evaluated factors, other than genetic, which might be related to the lack of an oxytocin-mediated insulinlike response (glucose oxidation; lipogenesis) in adipocytes from Brattleboro rats, homozygous for the diabetes insipidus trait (HoDI rats). The manoeuvres used in an attempt to restore the glucoregulatory responses to oxytocin in HoDI cells (increased glucose in the fat pad digestion medium; increased calcium concentration in the oxidation assay; estrogen treatment; use of [1-14C]glucose as substrate; inclusion of adenosine in the assay medium; vasopressin replacement therapy) uniformly failed to result in oxytocin activation of HoDI adipocytes, in contrast, the contractile responses of estrogenized HoDI rat uteri were indistinguishable from those of estrogenized normal rats. We conclude that the nonresponsiveness of the Brattleboro adipocytes to the glucoregulatory actions of oxytocin is not due to factors related to the conditions of the bioassay. On the other hand, in normal fat cells (from Sprague–Dawley and Long Evans rats), oxytocin responsiveness was augmented by a number of the manoeuvres mentioned above, most notably by the inclusion of either calcium (10 mM) or adenosine (10 μM) in the assay medium. Nonetheless, the maximum oxytocin responsiveness of adipocytes from Long Evans or Sprague–Dawley rats, under all conditions of assay, was still only a fraction (less than 20%) of the maximal response to insulin. The effect of adenosine on oxytocin action (increased sensitivity, without an effect on the maximum response) is in keeping with the previously observed effects of this nucleoside on the action of insulin; our results thus pointed to a new parallel in the action of insulin and oxytocin.

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