instruction:
Given an abstract, indicate which of the provided candidate titles (Option1 and Option2) best describes it (respond with the text of the title, not option1/2).
question:
Abstract: The influence of serotonin (5-hydroxytryptamine) on human detrusor and on pig detrusor, trigone, bladder neck and urethral smooth muscle was explored in a series of in vitro experiments. Serotonin evoked a dose-dependent and reversible contraction of the detrusor. The reverse response was triggered in trigone, bladder neck and urethral smooth muscle--a dose-dependent and reversible relaxation. The maximum amplitude of this relaxation was 85 +/- 15% of the relaxation produced by electrical nerve stimulation. The effect of serotonin was unaltered by blockade of ganglia, alpha- and beta-adrenergic receptors, cholinergic receptors and prostaglandin synthesis. The serotonin antagonists ketanserin, methysergide and cyproheptadine partly inhibited the effect of serotonin. The antagonism differed in potency on strips of different origin. The antagonists were ineffective or minimally effective in blocking responses to nerve stimulation. The effect of serotonin was probably mediated by specific serotonin receptors different from the serotonin-S2-receptors predominating in vascular smooth muscle. Serotonin is a potential neurotransmitter in lower urinary tract smooth muscle, but its importance in micturition physiology and pathophysiology is unknown.
Which is the apt title for the abstract? option1: Influence of serotonin on lower urinary tract smooth muscle in vitro. option2: Intestinal lymphangiectasia and bilateral pleural effusions: effect of dietary therapy and surgical intervention on immunologic and pulmonary parameters.
answer:
Influence of serotonin on lower urinary tract smooth muscle in vitro.

question:
Abstract: The human chorionic gonadotropin (hCG) beta subunit curve of normal singleton in vitro fertilization (IVF) pregnancies shows cyclic peaks during the first 56 days after embryo transfer (ET). This phenomenon is not demonstrable in normal spontaneous conceptions. The hCG curves of 151 singleton IVF pregnancies achieved by transfer of two, three, and four embryos therefore were compared statistically with the hCG curves of singleton IVF pregnancies achieved by transfer of only one embryo. The hCG levels of singleton IVF pregnancies achieved by transfer of more than one embryo had statistically higher hCG levels at 7 and 8, 19 and 20, and 37 and 38 days after ET. In a separate evaluation it was observed that declines in hCG levels of normal singleton IVF pregnancies preceded four of five first-trimester abortion incidence peaks of singleton IVF pregnancies. The observed cyclic hCG secretion may be indicative of early embryo deaths. This observation supports the contention that multiple ET results in significantly more multiple implantations than previously appreciated. Thus embryo survival in utero may represent another major contributory factor to success or failure of IVF.
Which is the apt title for the abstract? option1: Does cyclic human chorionic gonadotropin secretion indicate embryo loss in in vitro fertilization? option2: Heparin-induced thrombocytopenia and recurrent thrombosis in pregnancy. A case report.
answer:
Does cyclic human chorionic gonadotropin secretion indicate embryo loss in in vitro fertilization?

question:
Abstract: A product of the recent physical fitness boom has been an increased demand for better care of sport and recreational injuries. This article gives an overview of the care available for such injuries. In addition, it also cautions against the kind of care that will only produce noncompliance in the pediatric patient.
Which is the apt title for the abstract? option1: Sports medicine. option2: Parathyroid hormone reduces acute ischemic injury of the myocardium.
answer:
Sports medicine.