Dynamics of 125I-Labelled Horse Serum Albumin Presentation in vivo in Guinea Pigs

1991 ◽  
Vol 96 (3) ◽  
pp. 285-288
Author(s):  
Judit Pongracz ◽  
B. Csaba
1989 ◽  
Vol 61 (03) ◽  
pp. 463-467 ◽  
Author(s):  
G M Smith

SummaryIn this study, 5-hydroxytryptamine (5-HT) caused a dose- dependent fall in the circulating platelet count suggesting that 5-HT receptors are activated in rat platelets to cause platelet adhesion and aggregation. When low doses of adenosine diphosphate (ADP) were simultaneously injected with 5-HT, there was a significant potentiation of the responses to ADR Ketanserin significantly reduced the potentiated responses. When higher doses of ADP were infused with bolus injections of 5-HT there was no potentiation and ketanserin did not reduce these responses. Ketanserin did not inhibit the collagen-induced fall in circulating platelet count, but did significantly increase the rate of return to the basal platelet count compared with control. 5-HT did not cause a fall in platelet count in guinea-pigs


1976 ◽  
Vol 36 (02) ◽  
pp. 401-410 ◽  
Author(s):  
Buichi Fujttani ◽  
Toshimichi Tsuboi ◽  
Kazuko Takeno ◽  
Kouichi Yoshida ◽  
Masanao Shimizu

SummaryThe differences among human, rabbit and guinea-pig platelet adhesiveness as for inhibitions by adenosine, dipyridamole, chlorpromazine and acetylsalicylic acid are described, and the influence of measurement conditions on platelet adhesiveness is also reported. Platelet adhesiveness of human and animal species decreased with an increase of heparin concentrations and an increase of flow rate of blood passing through a glass bead column. Human and rabbit platelet adhesiveness was inhibited in vitro by adenosine, dipyridamole and chlorpromazine, but not by acetylsalicylic acid. On the other hand, guinea-pig platelet adhesiveness was inhibited by the four drugs including acetylsalicylic acid. In in vivo study, adenosine, dipyridamole and chlorpromazine inhibited platelet adhesiveness in rabbits and guinea-pigs. Acetylsalicylic acid showed the inhibitory effect in guinea-pigs, but not in rabbits.


1965 ◽  
Vol 13 (01) ◽  
pp. 065-083 ◽  
Author(s):  
Shirley A. Johnson ◽  
Ronaldo S. Balboa ◽  
Harlan J. Pederson ◽  
Monica Buckley

SummaryThe ultrastructure of platelet aggregation in vivo in response to bleeding brought about by transection of small mesenteric vessels in rats and guinea pigs has been studied. Platelets aggregate, degranulate and separating membranes disappear in parallel with fibrin appearance which is first seen at several loci after 30 seconds of bleeding. About 40 per cent of the electron opaque granules, some of which contain platelet factor 3 have disappeared after one minute of bleeding while the electron lucent granules increase by 70 per cent suggesting that some of them may be empty vesicles. Most of the platelet aggregates of the random type disappear leaving clumped red blood cells entrapped by a network of fibrin fibers which emanate from the remains of platelet aggregates of the rosette type to maintain hemostasis.


1975 ◽  
Vol 64 (2) ◽  
pp. 289-297 ◽  
Author(s):  
ILSE LASNITZKI ◽  
HILARY R. FRANKLIN

SUMMARY The influence of serum on the uptake, conversion and action of dihydrotestosterone in relation to the sex steroid binding protein, TeBG, has been investigated in rat ventral prostates in organ culture. The organs were incubated with [1,2-3H]dihydrotestosterone in: (1) serum-free medium, (2) horse serum, foetal and newborn bovine serum or (3) human male and human pregnancy serum. With all sera the uptake of dihydrotestosterone fell with rising serum concentration, at first steeply and then more gradually. At the same concentration, the uptake was significantly lower in explants incubated with human pregnancy serum than in those kept with human male serum. The conversion of dihydrotestosterone to androstanediol followed the same pattern and less androstanediol was formed in the presence of pregnancy serum. Since pregnancy serum contains higher amounts of TeBG than male serum, the lowered uptake suggests that only the free hormone was available to the target organ. Addition of unlabelled dihydrotestosterone resulted in a higher uptake than that measured in explants incubated with the labelled steroid only. The effect of the human sera on uptake and conversion was correlated with the androgenic activity of dihydrotestosterone applied at physiological concentrations and expressed as the percentage of secretory columnar cells present. The degree of maintenance closely corresponded to the uptake of the hormone. In serum-free medium, the number of columnar cells approached the values found in vivo, with male serum their number, though reduced, was still substantial, with pregnancy serum it was extremely low. It is concluded that the amounts of TeBG present in serum regulate the supply of the hormone to the target tissue and thus control its biological action.


1941 ◽  
Vol 141 (3) ◽  
pp. 999-1000
Author(s):  
Erwin Brand ◽  
Beatrice Kassell
Keyword(s):  

2021 ◽  
Author(s):  
Chao Zhang ◽  
Xusheng Guo ◽  
Xuwen Da ◽  
Yishan Yao ◽  
Haihua Xiao ◽  
...  

Ru(II)-based photoactivated chemotherapy (PACT) agents are promising, however, the short wavelength absorption (generally < 550 nm) and poor tumor accumulation ability limit their in vivo applications. Herein bovine serum albumin...


Sign in / Sign up

Export Citation Format

Share Document