scholarly journals Effects of l-NMMA and l-NNA on the Selective ATP-Induced Enhancement of Intratumoral Blood Flow

1992 ◽  
Vol 12 (1) ◽  
pp. 120-127 ◽  
Author(s):  
Y. Natori ◽  
M. Moriguchi ◽  
S. Fujiwara ◽  
I. Takeshita ◽  
M. Fukui ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Blood Flow ◽  
Blood Vessels ◽  
Inhibitory Action ◽  
The Other ◽  
Hydrogen Clearance Method ◽  
Other Hand ◽  
Selective Enhancement ◽  
Hydrogen Clearance

We studied the effects of NG-monomethyl-l-arginine (l-NMMA) and Nω-nitro-l-arginine (l-NNA) on the selective ATP and adenosine-induced enhancement of intratumoral blood flow in rats measured by the hydrogen clearance method. Both adenosine and ATP produced a selective enhancement of the intratumoral blood flow. Neither l-NMMA nor l-NNA had a significant effect on either the CBF or the intratumoral blood flow. Adenosine-induced enhancement was not inhibited by l-NMMA or l-NNA. On the other hand, the ATP-induced enhancement was totally inhibited by both l-NMMA and l-NNA. The inhibitory action of l-NMMA against ATP was blocked by l-arginine, but not by d-arginine. It is suggested that the ATP-induced increase of intratumoral blood flow is evoked by nitric oxide synthesized from the endothelium of the intratumoral blood vessels.

Measurement of local blood flow of the intestine by hydrogen clearance method; Experimental study

1979 ◽  
Vol 9 (1) ◽  
pp. 63-70 ◽  
Author(s):  
Yoshio Mishima ◽  
Hiroshi Shigematsu ◽  
Yoshiaki Horie ◽  
Masanori Satoh
Keyword(s):  
Experimental Study ◽  
Blood Flow ◽  
Local Blood Flow ◽  
Hydrogen Clearance Method ◽  
Hydrogen Clearance

scholarly journals Blood Perfusion of the Kidney of Lophius Piscatorius L.

1953 ◽  
Vol 32 (2) ◽  
pp. 329-336 ◽  
Author(s):  
L. Brull ◽  
E. Nizet ◽  
E. B. Verney
Keyword(s):  
Blood Flow ◽  
Critical Level ◽  
Perfusion Pressure ◽  
Blood Perfusion ◽  
Urine Flow ◽  
The Other ◽  
Protein Nitrogen ◽  
Other Hand ◽  
Flow Through

Lophius kidneys perfused with the heparinized blood (venous) of the fish secrete urine in which total non-protein nitrogen is concentrated, magnesium highly concentrated, and chloride only slightly so or not at all. Oxygenation of the blood, or lowering the temperature of the perfusate from c. 20° to c. 5° C. does not appear to influence secretion. The blood flow through the kidneys increases with the perfusion pressure, the increase often becoming disproportionately large. The urine flow, on the other hand, above a certain critical level is largely independent of changes in perfusion pressure.

scholarly journals The Role of Neuronal Nitric Oxide Synthase in Regulation of Cerebral Blood Flow in Normocapnia and Hypercapnia in Rats

1995 ◽  
Vol 15 (5) ◽  
pp. 774-778 ◽  
Author(s):  
Qiong Wang ◽  
Dale A. Pelligrino ◽  
Verna L. Baughman ◽  
Heidi M. Koenig ◽  
Ronald F. Albrecht
Keyword(s):  
Nitric Oxide ◽  
Blood Flow ◽  
Nitric Oxide Synthase ◽  
Inhibitory Action ◽  
Neuronal Nitric Oxide Synthase ◽  
Muscarinic Agonist ◽  
Doppler Flowmetry ◽  
Nos Inhibitors ◽  
Oxide Synthase

The nitric oxide synthase (NOS) inhibitors, nitro-L-arginine, its methyl ester, and N-monomethyl-L-arginine, have been shown to attenuate resting CBF and hypercapnia-induced cerebrovasodilation. Those agents nonspecifically inhibit the endothelial and neuronal NOS (eNOS and nNOS). In the present study, we used a novel nNOS inhibitor, 7-nitroindazole (7-NI) to examine the role of nNOS in CBF during normocapnia and hypercapnia in fentanyl/N2O-anesthetized rats. CBF was monitored using laser-Doppler flowmetry. Administration of 7-NI (80 mg kg−1 i.p.) reduced cortical brain NOS activity by 57%, the resting CBF by 19–27%, and the CBF response to hypercapnia by 60%. The 60% reduction was similar in magnitude to the CBF reductions observed in previous studies in which nonspecific NOS inhibitors were used. In the present study, 7-NI did not increase the MABP. Furthermore, the CBF response to oxotremorine, a blood–brain barrier permeant muscarinic agonist that induces cerebrovasodilation via endothelium-derived NO, was unaffected by 7-NI. These results confirmed that 7-NI does not influence eNOS; they also indicated that the effects of 7-NI on the resting CBF and on the CBF response to hypercapnia in this study were solely related to its inhibitory action on nNOS. The results further suggest that the NO synthesized by the action of nNOS participates in regulation of basal CBF and is the major, if not the only, category of NO contributing to the hypercapnic CBF response.

COMPARISON OF THE ANTI-FERTILITY AND SEX HORMONAL ACTIVITIES OF SEX HORMONES AND THEIR DERIVATIVES

1964 ◽  
Vol 47 (3) ◽  
pp. 444-456 ◽  
Author(s):  
P. A. Desaulles ◽  
C. Krähenbühl
Keyword(s):  
Sex Hormones ◽  
Relative Intensity ◽  
Sex Steroids ◽  
Inhibitory Action ◽  
Inhibitory Effect ◽  
The Other ◽  
Potent Effect ◽  
Other Hand ◽  
Activity Ratios ◽  
Blastocyst Implantation

ABSTRACT The following effects exerted by sex steroids were measured: androgenic, oestrogenic, and progestational effects; the inhibition action on gonadotrophic function in castrated animals; and the inhibitory action on ovulation and blastocyst implantation in intact animals. The steroids investigated consisted of oestradiol and its ethinyl and methoxyethinyl derivatives, oestrone, oestriol, testosterone, progesterone, and certain synthetic gestagens derived from nortestosterone, i. e. norethisterone, norethynodrel, and ethinyl-oestrenol. Oestradiol and its derivatives show potent anti-gonadotrophic activity, a relatively less potent anti-ovulatory effect, and a marked inhibitory action on implantation. Progesterone, on the other hand, which has only a very weak inhibitory effect on gonadotrophic function, shows an anti-ovulatory activity which, though inferior in absolute terms to that of oestradiol, is still appreciable, whereas it exerts almost no effect at all on implantation. With regard to its activity ratios, testosterone occupies a position mid-way between the two female hormones. Norethisterone, norethynodrel, and ethinyl-oestrenol have a more potent effect on gonadotrophic function than progesterone. The activity ratios for the effects of these three compounds on ovulation and implantation are comparable to those of oestradiol or progesterone, depending on the relative intensity of their oestrogenic and progestational action. The nature of the endocrine changes produced by these compounds are discussed with reference to the inhibition of ovulation and implantation.

Potentiating Effect of Adenosine on Other Inhibitors of Platelet Aggregation

1972 ◽  
Vol 27 (02) ◽  
pp. 252-262 ◽  
Author(s):  
M. Murakami ◽  
K. Odake ◽  
M. Takase ◽  
K. Yoshino
Keyword(s):  
Platelet Aggregation ◽  
Inhibitory Action ◽  
Prostaglandin E1 ◽  
Adenine Nucleotide ◽  
Adenine Nucleotides ◽  
Inhibitory Effect ◽  
Human Platelets ◽  
The Other ◽  
Other Hand ◽  
Adp Release

SummaryAdenosine was rapidly incorporated into human platelets, and the inhibitory effect of adenosine on platelet aggregation was correlated with the incorporation process. Adenosine potentiated the inhibitory action of other inhibitors, such as dipyridamole, prostaglandin E1 and Y-3642. The inhibition of aggregation was associated with the preservation of platelet adenine nucleotides and the prevention of ADP release. On the other hand, the radioactive adenine nucleotide pattern of platelets was not substantially affected by inhibitors. The relation of inhibition of aggregation with ADP release was discussed.

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