Plasma free and total tryptophan during the oestrus cycle,in ovariectomized and in male rats

Summary Plasma free tryptophan was higher during prooestrus and early oestrus than at metoestrus or in ovariectomized or male rats. In contrast, total tryptophan was higher in ovariectomized and male rats than at any time in cycling females.     

The physiological effects of ionic lanthanum on the insect blood-brain barrier

Summary Lanthanum had a small effect on the barrier, but did not significantly increase its sodium or patossium permeability. There was no effect on nerve conduction unless the barrier was deliberately damaged. The results lend confidence to the use of lanthanum as an extracellular tracer.     

A simple one-step procedure for staining the nucleolus organizer regions

Summary A simple silver staining technique for routine use is described by which the nucleolus organizer regions of mammalian chromosomes, including those of mouse chromosomes, are stained selectively.Acknowledgment. We would like to thank Prof. Dr K. Sperling for critical and helpful discussion.     

Setal relationships and their significance inA. pallipes

Summary The setae ofA. pallipes have a pattern of distribution. Many of the setae, although of a different type, are always found together. Such relationships can be linked with body functions.Acknowledgments to the Central Research Fund of the University of London who provided the financial assistance for this research work.     

Neuroleptic-induced prolactin rise: Influence of pharmacological alterations of different neurotransmitter systems

Summary Oral administration of 2 neuroleptic drugs, haloperidol and LR511 induced in male rats a marked, dose-dependent and sustained rise of plasma prolactin.     

The control of contraction activation by the membrane potential

Summary Force measurements under voltage-clamp control were performed in short toe muscles of the frog. The results show a) that the activation of force development and its repriming process can at least qualitatively be correlated to charge movement kinetics; b) that caffeine improves EC coupling by potentiating the potential dependent activation process.This work was supported by DFG (SFB 114 Bionach) and DAAD.     

Effective dose present in cockroach larvae exposed continuously to a juvenile hormone active insect growth regulator

Summary Larvae of the German cockroach exposed to filter paper impregnated with juvenile hormone (JH) active substance contain, at the middle of the last instar, about one-hundredth of the dose applied to 1 cm². The amount of metabolized substance rises sharply before and disappears rapidly after the ecdysis into the supernumerary instar.Acknowledgments. We wish to express our thanks to Prof. Dr H.A. Schneiderman, Dr W. Vogel and Dr P.A. Vonder Mühll for stimulating discussion and to Mr M. Gruber for correction of the text.