Trajectories and Milestones of Cortical and Subcortical Development of the Marmoset Brain From Infancy to Adulthood.

With increasing attention on the developmental causes of neuropsychiatric disorders, appropriate animal models are crucial to identifying causes and assessing potential interventions. The common marmoset is an ideal model as it has sophisticated social/emotional behavior, reaching adulthood within 2 years of birth. Magnetic resonance imaging was used in an accelerated longitudinal cohort (n = 41; aged 3-27 months; scanned 2-7 times over 2 years). Splines were used to model nonlinear trajectories of grey matter volume development in 53 cortical areas and 16 subcortical nuclei. Generally, volumes increased before puberty, peaked, and declined into adulthood. We identified 3 milestones of grey matter development: I) age at peak volume; II) age at onset of volume decline; and III) age at maximum rate of volume decline. These milestones differentiated growth trajectories of primary sensory/motor cortical areas from those of association cortex but also revealed distinct trajectories between association cortices. Cluster analysis of trajectories showed that prefrontal cortex was the most heterogenous of association regions, comprising areas with distinct milestones and developmental trajectories. These results highlight the potential of high-field structural MRI to define the dynamics of primate brain development and importantly to identify when specific prefrontal circuits may be most vulnerable to environmental impact.

Irsogladine maleate counters the interleukin-1 beta-induced suppression in gap-junctional intercellular communication but does not affect the interleukin-1 beta-induced zonula occludens protein-1 levels in human gingival epithelial cells.

BACKGROUND AND OBJECTIVE: Irsogladine maleate counters gap junctional intercellular communication reduction induced by interleukin-8 or Actinobacillus actinomycetemcomitans in cultured human gingival epithelial cells. Interleukin-1 beta is involved in periodontal disease. Little is known, however, about the effect of interleukin-1 beta on intercellular junctional complexes in human gingival epithelial cells. Furthermore, irsogladine maleate may affect the actions of interleukin-1 beta. In this study, we examined how interleukin-1 beta affected gap junctional intercellular communication, connexin 43 and zonula occludens protein-1, and how irsogladine maleate modulated the interleukin-1 beta-induced changes in the intercellular junctional complexes in human gingival epithelial cells. MATERIAL AND METHODS: Human gingival epithelial cells were exposed to interleukin-1 beta, with or without irsogladine maleate. Connexin 43 and zonula occludens protein-1 were examined at mRNA and protein levels by real-time polymerase chain reaction and western blotting, respectively. Gap junctional intercellular communication was determined using the dye transfer method. The expression of zonula occludens protein-1 was also confirmed by immunofluorescence. RESULTS: Interleukin-1 beta decreased connexin 43 mRNA levels, but increased zonula occludens protein-1 mRNA levels. Irsogladine maleate countered the interleukin-1 beta-induced reduction in gap junctional intercellular communication and connexin 43 levels. However, irsogladine maleate did not influence the increased zonula occludens protein-1 levels. CONCLUSION: The effect of interleukin-1 beta on gap junctional intercellular communication and tight junctions of human gingival epithelial cells is different. The recovery of gap junctional intercellular communication by irsogladine maleate in the gingival epithelium may be a normal process in gingival epithelial homeostasis.

Intercellular communication capacity as a possible determinant of transformation sensitivity of BALB/c 3T3 clonal cells.

While clonal cell variants of BALB/c 3T3 with high and low susceptibilities to ultraviolet radiation- and benzo(a)pyrene-induced transformation show similar intercellular communication capacities when they are in the growing phase, a significant loss in communication occurs at confluence only in transformation-sensitive clonal variant cells. A potent tumor promoter, 12-O-tetradecanoylphorbol-13-acetate, which also enhances BALB/c 3T3 cell transformation induced by methylcholanthrene, inhibited intercellular communication of these variants to a similar extent. These results suggest that intrinsic differences in the control of intercellular communication may be a determinant of the susceptibility of these variants to the induction of transformation.

Augmentation of hepatic glucose uptake by a positive glucose gradient between hepatoportal and central nervous systems.

To determine the role of the glucose gradient between the hepatoportal system (HPS) and the central nervous system (CNS) in regulating hepatic glucose uptake, experiments were conducted with seven conscious dogs using a hepatic venous catheterization technique. With the infusion of somatostatin (0.8 microg x kg(-1) x min(-1)), glucagon (0.65 ng x kg(-1) x min(-1)), and insulin (27 pmol x kg(-1) x min(-1)), arterial glucose levels could be maintained at 8 mmol/l by adjusting the intravenous glucose infusion (G(inf)) according to the following three periods: 1) peripheral glucose infusion period (PE), G(inf) alone; 2) portal glucose infusion period (PO), G(inf) plus constant glucose infusion into the portal vein (GIR(PV), 55.6 micromol x kg(-1) x min(-1)); 3) portal and brain glucose infusion period (PO+CNS), G(inf) and GIR(PV) plus additional glucose infusion into the unilateral carotid and vertebral arteries to abolish the positive glucose gradient between HPS and CNS. Arterial plasma glucose levels were clamped during the three periods (8.1 +/- 0.1, PE; 8.2 +/- 0.1, PO; 8.2 +/- 0.1 mmol/l, PO+CNS). During PO, when a positive glucose gradient was promoted between HPS and CNS, the net hepatic glucose balance (NHGB) determined by the difference between hepatic glucose inflow and outflow was significantly lower than that of PE (-41.5 +/- 5.3, PO vs. -7.5 +/- 3.4 micromol x kg(-1) x min(-1), PE; P < 0.01). However, this decrease in the NHGB significantly increased during PO+CNS, when the glucose gradient between HPS and CNS was minimized, compared with PO (-21.7 +/- 3.2 micromol x kg(-1) x min(-1), P < 0.05). We conclude that a positive glucose gradient between HPS and CNS is an important regulatory factor of hepatic glucose uptake, but other factors also play important roles because minimizing the glucose gradient between HPS and CNS diminished the net hepatic glucose uptake by 50%.

Visualization of the secretory process involved in Ca2+-activated fluid secretion from rat submandibular glands using the fluorescent dye, calcein.

The central feature of fluid and electrolyte secretion by salivary acinar cells is transepithelial Cl- movement as a driving force for the secretion. However, little is known about the membrane localization and regulation by agonists of various anion channels. To characterize the anion transport and fluid secretion, we visualized the secretory process induced by the cholinergic agonist, carbachol (CCh), using the anionic fluorescent dye, calcein, under a confocal laser scanning microscope. The fluorescence of calcein loaded into the isolated acini was spread diffusely throughout the cytoplasm and was less intense in the secretory vesicles which occupied the apical pole. Cytoplasmic calcein was released into intercellular canaliculi just after the addition of CCh, depending upon a rise in [Ca2+]i by Ca2+ release from intracellular stores. Thereafter, the formation of watery vacuoles connected with intercellular canaliculi was visualized in the calcein-loaded acini, depending upon external Ca2+. Both the calcein release and vacuole formation were inhibited by suppressing the Ca(2+)-activated K+ efflux. The calcein release was also affected by the external anion substitution, suggesting that calcein is released through an anion channel. In the isolated, perfused glands, CCh-induced fluid secretion was sustained in two phases, whereas the loaded calcein was initially and transiently released into the saliva. By revealing the [Ca2+]i dependence and sensitivities to channel blockers, our results suggest that the initial phase of CCh-induced fluid secretion was evoked in association with the release of the organic anion, calcein, and the late phase of fluid secretion, during which calcein is less permeable, was associated with the formation of watery vacuoles. Thus, the anion channels possessing the distinct property of anion permeation may be activated in the initial phase and late phase. These results indicate that the anionic fluorescent dye, calcein, is useful for visualizing the process of Ca(2+)-dependent fluid secretion, and for clarifying the relation between fluid secretion and anion transport.

Important role of the hepatic vagus nerve in glucose uptake and production by the liver.

We examined the role of the hepatic vagus nerve in hepatic and peripheral glucose metabolism. To assess endogenous glucose production (EGP), hepatic uptake of first-pass glucose infused intraportally (HGU), and the metabolic clearance rate of glucose (MCR), rats were subjected to hepatic vagotomy (HV, n = 7) or sham operation (SH, n = 8), after 10 days, they were then subjected to a euglycemic-hyperinsulinemic clamp together with a portal glucose load in the 24-hour fasting state. Metabolic parameters were determined by the dual-tracer method using stable isotopes. During the experiment, [6,6-2H2]glucose was continuously infused into the peripheral vein. To maintain euglycemia (4.5 mmol/L), insulin (54 pmol x kg(-1) x min(-1)) and glucose were infused peripherally after the 90-minute tracer equilibration and 30-minute basal periods, and glucose containing 5% enriched [U-13C]glucose was infused intraportally (50 micromol x kg(-1) x min(-1)) for 120 minutes (clamp period). EGP was significantly higher in HV rats versus SH rats during the basal period (64.3 +/- 7.6 v 43.6 +/- 5.3 micromol x kg(-1) x min(-1), P < .005)) and was comparable to EGP in SH rats during the clamp period (9.3 +/- 21.5 v 1.1 +/- 11.7 micromol x kg(-1) x min(-1)). HGU was reduced in HV rats compared with SH rats during portal glucose infusion (5.9 +/- 2.4 v 10.1 +/- 3.2 micromol x kg(-1) x min(-1)). The MCR in HV rats was significantly higher than in SH rats in the basal period (11.0 +/- 2.0 v 7.9 +/- 0.8 mL x kg(-1) x min(-1), P < .01)) and was comparable to the MCR in SH rats during the clamp period (41.9 +/- 10.0 and 36.6 +/- 5.7 mL x kg(-1) x min(-1)). We conclude that innervation of the hepatic vagus nerve is important for the regulation of hepatic glucose production in the postabsorptive state and HGU in the postprandial state.

Increased hepatic glucose production and decreased hepatic glucose uptake at the prediabetic phase in the Otsuka Long-Evans Tokushima fatty rat model.

To investigate the time course of the hepatic glucose metabolism in non-insulin-dependent diabetes (NIDDM), we measured hepatic glucose production (HGP) and first-pass uptake of portal glucose infusion by the liver (HGU) using dual-tracer methods in a NIDDM model, Otsuka Long-Evans Tokushima Fatty (OLETF) rats, and in normal controls, Long-Evans Tokushima Otsuka (LETO) rats, at 8, 14, and 28 weeks of age (n = 5, respectively). The fasting plasma glucose level in OLETF rats was significantly higher than in LETO rats at 28 weeks of age (8.9 +/- 1.7 v 6.3 +/- 0.4 mmol/L, P < .01), while there was no significant difference at 8 and 14 weeks. Hyperinsulinemia in OLETF rats appeared at > or = 8 weeks of age. Basal HGP was significantly higher in OLETF than in LETO rats at 8 and 28 weeks (8 weeks, 12.7 +/- 1.7 v 9.4 +/- 1.8 mg x kg(-1) x min(-1), P < .05; 28 weeks, 10.9 +/- 1.6 v 7.1 +/- 1.3 mg x kg(-1) x min(-1), P < .01). At 14 weeks, basal HGP was not significantly different between OLETF and LETO rats. However, at all study points, HGU during a portal glucose infusion was significantly lower in OLETF than in LETO rats (8 weeks, 0.9 +/- 0.2 v 2.3 +/- 0.5, P < .01; 14 weeks, 0.8 +/- 0.3 v 1.4 +/- 0.3, P < .05; 28 weeks, 0.7 +/- 0.2 v 1.4 +/- 0.3 mg x kg(-1) x min(-1), P < .01). Fasting plasma free fatty acid (FFA) levels were not significantly different between OLETF and LETO, except at 8 weeks. Suppression of plasma FFA levels by endogenous insulin during a portal glucose infusion was impaired in OLETF rats compared with LETO rats. In summary, this study demonstrates that derangement of hepatic glucose handling, such as increased basal HGP and decreased HGU, is observed in obese NIDDM model OLETF rats at the prediabetic phase when hyperglycemia is still not apparent. Furthermore, these derangements may be accompanied by impaired lipid metabolism.

Immunocytochemical localization of motilin-containing cells in the rabbit gastrointestinal tract.

Motilin-immunopositive cells (Mo cells) are known to be present in the upper small intestine of various species, including man. However, whether Mo cells are present in the rabbit gastrointestinal tract remained to be elucidated. Therefore, this study was designed to investigate the distribution of Mo cells in the rabbit gastrointestinal tract by the avidin-biotin-peroxidase complex method using a new anti-motilin serum (CPV2) raised in chickens. The results of an enzyme-linked immunosorbent assay suggested that this antiserum recognized the C-terminal region of the motilin molecule. Motilin-immunopositive cells were found in the epithelia of the crypts and villi throughout the rabbit gastrointestinal tract from the gastric antrum to the distal colon, but no immunostaining occurred in the gastric body. Morphometric analysis revealed that Mo cells were localized preferentially in the upper small intestine, as reported for other species, and the cell densities (cells/mm2, mean +/- SE) were: gastric antrum (0.41 +/- 0.16), duodenum (8.2 +/- 0.8), jejunum (1.9 +/- 0.5), ileum (0.62 +/- 0.14), cecum (0.19 +/- 0.05), proximal colon (0.13 +/- 0.03), and distal colon (0.39 +/- 0.18). Our results demonstrated conclusively that Mo cells exist in the rabbit gastrointestinal tract and showed for the first time their regional distribution. Furthermore, our new chicken antiserum would appear to be a useful tool for the determination of plasma motilin concentrations by radioimmunoassay and for the immunoneutralization of endogenous motilin in the rabbit.

Autoradiographic study of motilin binding sites in the rabbit gastrointestinal tract.

Although motilin receptors have been demonstrated by ligand binding studies, there have been no morphological studies of motilin binding site distribution. Light microscopic macro- and micro-autoradiography using highly purified iodinated Tyr23 canine motilin (10(-10) M) was carried out on the gastric antrum, duodenum, cecum and distal colon of the rabbit. Motilin binding sites were found on the smooth muscle layers of the gastric antrum, duodenum and colon, but no positive binding reaction was detected in that of the cecum. Specific binding sites were particularly abundant in the circular muscle layers, with low concentrations in the longitudinal muscle layers of the gastric antrum, duodenum and colon. No motilin binding sites were found in the mucosa of the gastrointestinal tract and pancreas. The intensity of the positive reaction was inhibited when the tissue was incubated with 10(-8) M unlabeled motilin and was completely abolished by 10(-7) M unlabeled motilin. These results are consistent with the difference in contractile response to motilin between the muscle layers of the gastrointestinal tract.

Effect of 5-hydroxytryptamine on gastrointestinal motility in conscious guinea-pigs.

Many studies have suggested that 5-hydroxytryptamine (5HT, serotonin) plays an important role in the control of gastrointestinal motility. However, most of these studies have been carried out on guinea-pig ileum in vitro. Therefore, we investigated the mechanisms of action of 5HT on gastrointestinal motility in conscious guinea-pigs. In order to investigate the effects of 5HT on gastrointestinal motility, extraluminal force transducers were sutured onto the serosal surfaces of the gastric antrum, duodenum and ileum and 5HT was infused intravenously. One of three types of 5HT antagonist or atropine was given before a 5HT infusion of 3.0 micrograms kg-1 min-1 was started. Regular cyclic patterns were observed from the gastric antrum to the ileum in both the fasted and fed states. 5HT increased the contraction amplitudes at all sites. 5HT-induced contractions in the gastric antrum and duodenum were significantly inhibited by methysergide, ondansetron and atropine, but not by ketanserin. In the ileum, only atropine inhibited 5HT-induced contractions. These results suggest that 5HT increases the gastrointestinal contraction amplitude mainly via a cholinergic pathway. 5HT3 receptors and 5HT1-like and/or 5HT2C receptors appear to be responsible for 5HT-induced gastric antral and duodenal contractions, but 5HT receptors other than 5HT1-like, 5HT2A, 5HT2C and 5HT3 receptors induce ileal contractions.

Effect of TKS159, a novel 5-hydroxytryptamine4 agonist, on gastric contractile activity in conscious dogs.

A novel 5-hydroxytryptamine (5-HT)4 receptor agonist, TKS159, ¿4-amino-5-chloro-2-methoxy-N-[(2S,4S)-1-ethyl-2- hydroxymethyl-4-pyrrolidinyl] benzamide), has recently been developed as a gastroprokinetic drug. Cisapride is already used clinically to increase gastric contractions. The stimulatory effects of TKS159 and cisapride on gastric contractions were examined using force transducers chronically implanted on the vagally denervated pouch (Heidenhain pouch) and the vagally innervated main stomach in conscious dogs. Contractile activity was analysed by computer and expressed as a motor index. Intravenous administration of TKS159 or cisapride significantly increased the motor index in both the main stomach and the Heidenhain pouch during the fed and fasted states. Pharmacological characterization in the fasted state revealed that the contraction-stimulating activity of TKS159 and cisapride on the stomach was significantly inhibited by atropine, hexamethonium and a 5-HT4 receptor antagonist, SDZ 205-557. Granisetron (a 5-HT3 receptor antagonist) significantly inhibited cisapride-induced, but not TKS159-induced gastric contractions. The plasma motilin concentration was significantly increased after cisapride, but not after TKS159 injection. In conclusion, TKS159 has a contractile-stimulating effect on both the innervated and the denervated stomach. It is likely that a cholinergic pathway and 5-HT4 receptors are involved in producing the contractions, although other mechanisms cannot be excluded. Cisapride has almost the same characteristics, but the present findings suggest the involvement of motilin and 5-HT3 receptors in the effects of cisapride.

cAMP-Dependent potentiation of the Ca(2+)-activated release of the anionic fluorescent dye, calcein, from rat parotid acinar cells.

A recent study indicates that elevation of [Ca(2+)](i) enhances the release of calcein, an anionic fluorescent dye, from isolated exocrine acinar cells, so cytoplasmic calcein is useful for monitoring the secretion of organic anions. In this study, we investigated the effect of cAMP on the calcein release evoked by elevation of [Ca(2+)](i). Isoproterenol, forskolin and dibutyryl cyclic AMP (dbcAMP) did not induce the release of calcein from isolated parotid acinar cells, but they potentiated the carbachol-induced release of calcein. Although cytoplasmic calcein is released through an increase in [Ca(2+)](i), isoproterenol potentiated the carbachol-induced release of calcein without affecting the increase in [Ca(2+)](i) evoked by a high concentration of carbachol (10(-6) M). Charybdotoxin, a K(+) channel blocker, inhibited both the carbachol-induced release and the potentiation by isoproterenol. However, the calcein permeation pathways mediating the carbachol-induced release and the isoproterenol-potentiated release exhibited distinct sensitivities to anion channel blockers. Our results indicate that the calcein release induced by carbachol is potentiated through an increase in intracellular levels of cAMP. Although both the Ca(2+)-activated release and the cAMP-potentiated release may be coupled to Ca(2+)-activated K(+) efflux, increases in both [Ca(2+)](i) and [cAMP](i) may activate the calcein conduction pathway which is not activated by an increase in [Ca(2+)](i) alone.

Selective alpha 1-adrenergic inhibition improves decrease glucose disposal in patients with essential hypertension.

This study evaluated insulin secretion and insulin sensitivity before and after short-term oral administration of doxazosin in patients with essential hypertension. The hypertensive group consisted of 11 nonobese subjects (aged 41.0 +/- 2.5 years (mean +/- SEM), body mass index 24.0 +/- 0.53 kg/m2). The normotensive group consisted of 12 subjects matched to the hypertensive group for age and body mass index. The hypertensive group showed significantly higher concentrations of prestimulated and stimulated plasma insulin and plasma C peptide than normal groups. The insulin-mediated glucose disposal rate during euglycaemic clamp (M-value) was significantly lower in the hypertensive group than in normal controls (7.32 +/- 0.56 vs 8.88 +/- 0.34 mg/kg/min, P < 0.05). After one month of doxazosin treatment blood pressure was significantly reduced (P < 0.05). The short-term administration of doxazosin improved the M-value significantly to 8.60 +/- 0.62 mg/kg/min without a significant change in stimulated plasma C-peptide level. These data show that hypertension is associated with increased insulin secretion and impaired insulin sensitivity. Selective alpha 1-adrenergic inhibition with doxazosin improves the decreased glucose disposal rate associated with hypertension.

Insulin resistance in essential hypertensive patients with impaired glucose tolerance.

This study evaluated insulin secretion and insulin sensitivity in 17 non-obese hypertensive patients (aged 45.6 +/- 2.2 years, body mass index 24.0 +/- 0.5 kg/m2, mean +/- S.E.M.) with (n = 8) and without glucose intolerance (n = 9) and compared the results with those of 16 age-matched non-obese normotensive subjects with (n = 7) and without glucose intolerance (n = 9). The hypertensive patients without glucose intolerance showed a significantly lower insulin-mediated glucose disposal and a compensating increase in second-phase insulin secretion compared with normotensives without glucose intolerance. In hypertensives with glucose intolerance, insulin-mediated glucose disposal was significantly lower and second-phase insulin secretion was comparable to that in normotensives without glucose intolerance. After 3 months of angiotensin-converting enzyme (ACE) inhibition with oral administration of delapril, blood pressure was significantly reduced in the hypertensives with glucose intolerance (n = 9). The insulin-mediated glucose disposal significantly (P < 0.01) recovered from 6.0 +/- 0.81 to 8.0 +/- 0.71 mg/kg per min. The second-phase insulin secretion tended to be lower (but not significantly) but insulin clearance increased from 15.4 +/- 0.85 to 19.1 +/- 1.42 ml/min (P < 0.05). These data show that in hypertensive patients without glucose intolerance insulin resistance might compensatorily augment second-phase insulin secretion and lead to hyperinsulinemia. In hypertensives with glucose intolerance, insulin resistance might induce postprandial hyperglycemia, which leads to hyperinsulinemia because of second phase insulin secretion at a level similar to that of normotensives.

Effect of strict metabolic control on glucose handling by the liver and peripheral tissues in non-insulin-dependent diabetes mellitus.

To examine the effect of strict glycemic control on the insulin resistance of non-insulin-dependent diabetes mellitus (NIDDM), we applied euglycemic hyperinsulinemic clamp combined with an oral glucose load (OGL) to nine non-obese subjects with NIDDM and quantitated insulin-mediated glucose uptake by the liver (HGU) and peripheral tissues (PGU) simultaneously before and after 3 to 4 weeks of intimate glycemic control by preprandial regular insulin injections 3 times a day. The glucose infusion rate (GIR) required to maintain euglycemia during the clamp before OGL was considered as PGU. After OGL, the fraction of ingested glucose that is not extracted by the liver enters the systemic circulation and reduces the GIR required for the clamp. HGU was calculated from the difference between the amount of OGL and the cumulative decrements in GIR after OGL and was expressed as the ratio to the amount of OGL (%). Three to 4 weeks after initiation of strict metabolic control, FPG and HbA1c levels significantly improved (9.1 +/- 0.5 vs. 6.4 +/- 0.4 mmol/l, and 11.2 +/- 0.8 vs. 8.3 +/- 0.3%, P < 0.05). HGU significantly increased to 33.1 +/- 9.5 from 14.5 +/- 4.8%, while PGU did not change (38.2 +/- 5.2 vs. 37.4 +/- 3.9 mumol/kg.min). These data suggest that short-term strict metabolic control ameliorates insulin resistance in NIDDM mainly at the hepatic level.

Effects of denervation on cell-to-cell communication between acinar cells of rat submandibular salivary gland.

Communication measured by electrical cell coupling and dye transfer decreased transiently 1 day after parasympathectomy and then recovered 2 days later. Parasympathectomy decreased communication again 2 weeks later, coinciding with a decrease in the wet weight of the gland, but sympathectomy did not affect it. Thus parasympathetic nerve activity may be required for the regulation and maintenance of cell-to-cell communication in the rat submandibular gland.

Effect of ethanol on the production of carboxypeptidase Y using the GAL10 promoter in a Saccharomyces cerevisiae gal80 mutant.

In the course of studying carboxypeptidase Y (CPY) production, we found that the expression level of the gene, which is under the control of the GAL10 promoter, increased in a Saccharomyces cerevisiae gal80 mutant grown in a medium containing ethanol as the sole carbon source. In the cultivation of the gal80 mutant KS58-2D/pCY303 carrying a multicopy plasmid, which contains the PRC1 gene fused to the GAL10 promoter, CPY production continued after the consumption of galactose. In this phase, the cells utilized ethanol as the carbon source. To increase the CPY production level, we examined the effect of carbon source feeding in a fed-batch culture. The production level in the fed-batch culture using ethanol was 1.3-fold higher than that in a batch culture and 1.6-fold higher than that in a fed-batch culture using galactose. By 5'-deletion analysis of the GAL10 promoter, the region between -256 and -232 was found to be important for the promoter activity in the gal80 mutant growing in the presence of ethanol.

Process development for industrial-scale preparation of carboxypeptidase Y secreted by Saccharomyces cerevisiae.

A method for industrial-scale preparation of carboxypeptidase Y (CPY), which was secreted by Saccharomyces cerevisiae KS58-2D/pCY303 into the culture broth, was developed. Because the purification process consists of a few simple unit operations including only one chromatography step, a higher CPY recovery was achieved than that in the process using disrupted baker's yeast. Approximately 100 g of purified CPY powder was constantly obtained using the final culture broth from a 500-l fermentor.

Suppression of intercellular communication in acinar cells from rat submandibular gland by cholinergic and adrenergic agonists.

The effects of cholinergic and adrenergic agonists on intercellular communication in isolated acini of rat submandibular gland were evaluated using dye-coupling. Cells injected with Lucifer Yellow CH showed diffusion of the dye to their coupled neighbors under the control condition. Addition of acetylcholine (ACh) and carbachol (CCh) at concentrations higher than 10(-6) M rapidly and reversibly suppressed the dye-coupling. This effect by 10(-4) M ACh or 10(-4) M CCh was blocked by the addition of 10(-6) M atropine. The suppressive effects of 10(-4) M adrenaline and 10(-4) M noradrenaline were weaker than those of 10(-4) M ACh. Treatment with 10(-4) M isoproterenol did not inhibit the dye-coupling and the suppressive effect by 10(-4) M adrenaline was blocked by the addition of 10(-5) M phenoxybenzamine. The inhibition of dye-coupling by ACh and adrenaline was blocked by the addition of 10(-5) M verapamil, 10(-4) M W-7 and 1.5 x 10(-5) M H-7, but not by 1.5 x 10(-5) M HA1004. These results suggest that the muscarinic action of cholinergic agonists and the alpha-action of adrenergic agonists might suppress the intercellular communication of the acinar cells in the rat submandibular gland, possibly through the increase of calcium influx and the activation of protein kinase C.