Alleles ; General Surgery ; methods ; Genetic Variation ; Humans ; Hypotension ; drug therapy ; Receptors, Adrenergic, beta-2 ; genetics ; metabolism ; Vasoconstrictor Agents ; administration & dosage

To evaluate the feasibility of treating hypertension by human tissue kallikrein gene (KLK1) delivery and by enzyme (rK1) administration, two recombinant vectors expressing KLK1 cDNA were constructed for gene delivery (pcDNA-KLK1) and recombinant enzyme preparation (pOV-KLK1). Expression of the pcDNA-KLK1 vector in COS-1 cells was confirmed by immunofluorescence and in spontaneous hypertension rats (SHR) by enzymatic detection. Following intramuscular or intravenous injection with the pcDNA-KLK1 vector, systolic pressure of SHR was significantly decreased, which lasted for 20 d to two months depending on dose, route and/or time of injection. Egg white containing recombinant hK1 was prepared by injection of egg-laying hens with the oviduct-specific expression vector pOV-KLK1 and administered into SHR via oral gavage. Following administration, systolic pressure of the SHR was decreased to that of normal rats, which lasted for 3-5 d depending on the dosage used. These data suggest that both hKLK1 gene delivery and recombinant enzyme administration can be used as alternative strategies for treating human hypertension.
Animals ; Blood Pressure/physiology ; COS Cells ; Cercopithecus aethiops ; Chickens ; Female ; Gene Therapy ; *Gene Transfer Techniques ; Genetic Vectors/genetics/metabolism ; Humans ; Hypertension/genetics/*therapy ; Hypotension/genetics/*metabolism ; Rats ; Rats, Inbred SHR ; Recombinant Proteins/administration & dosage/genetics/metabolism/*therapeutic use ; Tissue Kallikreins/*genetics/metabolism

BACKGROUNDVascular hyporeactivity, which occurs in the terminal stage of hemorrhagic shock, is believed to be critical for treating hemorrhagic shock. The present study was designed to examine whether the CB1 cannabinoid receptor (CB1R) was involved in the development of vascular hyporeactivity in rats suffering from hemorrhagic shock.

METHODSSixteen animals were randomly divided into two groups (n = 8 in each group): sham-operated (Sham) and hemorrhagic shock (HS) groups. Hemorrhagic shock was induced by bleeding. The mean arterial pressure (MAP) was reduced to and stabilized at (25 +/- 5) mmHg for 2 hours. The vascular reactivity was determined by the response of MAP to norepinephrine (NE). In later experiments another twelve animals were used in which the changes of CB1R mRNA and protein in aorta and superior mesenteric artery (SMA) were analyzed by RT-PCR and Western blotting. In addition, we investigated the effects of a CB1R antagonist on the vascular hyporeactivity and survival rates in rats with hemorrhagic shock. Survival rates were analyzed by the Fisher's exact probability test. The MAP response was analyzed by one-way analysis of variance (ANOVA).

RESULTSVascular hyporeactivity developed in all animals suffering from hemorrhagic shock. The expression of CB1R mRNA and protein in aorta and 2 - 3 branches of the SMA were significantly increased in the HS group after the development of vascular hyporeactivity when compared to those in Sham group. When SR141716A or AM251 was administered, the MAP response to NE was (41.75 +/- 4.08) mmHg or (44.78 +/- 1.80) mmHg respectively, which was higher than that in saline groups with (4.31 +/- 0.36) mmHg (P < 0.01). We also showed an increased 4-hour survival rate in the SR141716A or AM251-treated group with 20% or 30%, but with a statistically significant difference present between the AM251-treated and saline groups (P < 0.05).

CONCLUSIONSCB1R is involved in vascular hyporeactivity resulting from hemorrhagic shock in rats, and CB1R antagonist may be useful in treating patients with traumatic, hemorrhagic shock who need field-rescue or initial treatment.

Animals ; Blotting, Western ; Gene Expression Regulation ; drug effects ; Hypotension ; metabolism ; Male ; Piperidines ; pharmacology ; Pyrazoles ; pharmacology ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Receptor, Cannabinoid, CB1 ; antagonists & inhibitors ; genetics ; metabolism ; physiology ; Reverse Transcriptase Polymerase Chain Reaction ; Shock, Hemorrhagic ; metabolism ; mortality ; Survival Rate

AIMTo study the effect of fetus hypobaric hypoxia on the number and channel character of NMDA receptor of hippocampus neurons.

METHODSUse in situ hybridization and patch-clamp techniques.

RESULTSAfter hypobaric hypoxia the number of NMDA mRNA positive neurons was decreased, the open probability of NMDA receptor was reduced, the open time constant was decreased, the close time constant was increased.

CONCLUSIONHypobaric hypoxia may change the development of NMDA receptor in fetus rat, then maybe effect learning and memory.

Animals ; Cell Hypoxia ; Fetus ; physiopathology ; Hippocampus ; cytology ; physiopathology ; In Situ Hybridization ; Intracranial Hypotension ; physiopathology ; N-Methylaspartate ; metabolism ; Neurons ; pathology ; Patch-Clamp Techniques ; RNA, Messenger ; genetics ; Rats ; Receptors, N-Methyl-D-Aspartate ; metabolism