Both olfactory epithelial and vomeronasal inputs are essential for activation of the medial amygdala and preoptic neurons of male rats.

Chemosensory inputs signaling volatile and nonvolatile molecules play a pivotal role in sexual and social behavior in rodents. We have demonstrated that olfactory preference in male rats, that is, attraction to receptive female odors, is regulated by the medial amygdala (MeA), the cortical amygdala (CoA), and the preoptic area (POA). In this paper, we investigated the involvement of two chemosensory organs, the olfactory epithelium (OE) and the vomeronasal organ (VNO), in olfactory preference and copulatory behavior in male rats. We found that olfactory preferences were impaired by zinc sulfate lesion of the OE but not surgical removal of the VNO. Copulatory behaviors, especially intromission frequency and ejaculation, were also suppressed by zinc sulfate treatment. Neuronal activation in the accessory olfactory bulb (AOB), the MeA, the CoA, and the POA was analyzed after stimulation by airborne odors or soiled bedding of estrous females using cFos immunohistochemistry. Although the OE and VNO belong to different neural systems, the main and accessory olfactory systems, respectively, both OE lesion and VNO removal almost equally suppressed the number of cFos-immunoreactive cells in those areas that regulate olfactory preference. These results suggest that signals received by the OE and VNO interact and converge in the early stage of olfactory processing, in the AOB and its targets, although they have distinct roles in the regulation of social behaviors.

Separation of phosphatidylinositol 4-phosphate from a mixture with phosphatidylserine and phosphatidylinositol by Sep-Pak C18 cartridge.

A simple and efficient method for the separation of phosphatidylinositol 4-phosphate (PI 4-P) from phosphatidylinositol (PI) and phosphatidylserine (PS) is described. A mixture of PI, PI 4-P and PS was injected onto a Sep-Pak C18 cartridge. PI and PS were flushed through the cartridge with solvent 1 [methanol-chloroform (3: 1)] while PI 4-P remained in it. Then the cartridge was inverted, and PI 4-P was eluted backward with solvent 2 [chloroform-methanol-0.5 M aqueous ammonium hydroxide (9:7:2)].

Serum cholesterol reduction and cholesterol absorption inhibition in CaCo-2 cells by a soyprotein peptic hydrolyzate.

The serum cholesterol level in rats was significantly decreased in a group fed on a soyprotein peptic hydrolyzate (SPH) when compared with a group fed on a casein tryptic hydrolyzate (CTH). The fecal excretion of total steroids was significantly greater with rats fed on the SPH diet when compared with the CTH diet. The results of CaCo-2 studies clearly suggest that the suppression of cholesterol absorption in the intestinal epithelia is part of the mechanism for the hypocholesterolemic action induced by SPH.

Measurement of the zeta potential of human platelets by the use of laser-light scattering.

An instrument was developed to detect the shift in scattering of laser light that occurs when particles in suspension move in a chamber with an electrical load. The instrument measures the zeta potential of particles. We applied the instrument to study human blood cells. Platelet-rich plasma was used because of the stability of the suspension, without the sedimentation or autoaggregation that is often seen with red or white blood cells. The reproducibility of the measurements was satisfactory when there were enough platelets in the suspension. Platelets from healthy controls (n = 136) had a potential of -14.20 +/- 1.64 mV at the detection angle of 17.1 degrees. Platelets from patients with essential thrombocytosis (n = 16) or polycythemia vera (n = 8) had higher potentials than the healthy controls.